It is crucial that you analyze the answer choices, not from a perspective of asking which is grammatically correct (they all will be) or even which sounds the best (they all might sound equally good) but how they are able to fulfil the desired outcome as specified in the question.
The following are the types of command of evidence questions that you may encounter:
Evidence questions ask you to find the best piece of evidence that supports an idea or claim in a sentence. You must pick the answer choice that is directly related to the point of the sentence, and also supports whatever that point is.
Oxford University’s Bodleian Library System is considered one of the most important research libraries in the world; the library’s famous Radcliffe Camera is located in the city centre.
Which of the following best supports the claim that this library is one of the most important research libraries in the world?
A. NO CHANGE
B. There are many libraries around the world that have far more scholarly significance.
C. It houses nearly 12 million books and thousands of ancient texts
D. Thousands of students attend Oxford University.
Answer choice C actually gives some reasons for why this library might be so important! C is the answer.
Although it is less well-known than other European cities, Prague has some of the most unique architecture in the world.
Which would be the most effective next sentence, given that the writer wants to add an example of the statement made in the above sentence?
A. Many of the buildings in the city are centuries old.
B. Prague was once the capital of the Holy Roman Empire.
C. One of its universities, Charles University, is one of the oldest in the world.
D. Even the cluster of buildings in Prague Castle differ greatly in the styles of their design.
Solution: Answer choices A is about buildings, but not architecture. Answer choices B and C contain historical information, not architectural. The only choice that discusses architecture, or the design of buildings and other structures is D, which is the correct answer.
One reason that honey doesn’t spoil involves the chemical make-up of the substance itself. Honey is extremely acidic, with a pH that falls between 3 and 4.5, depending on its floral source. As a result, invading microorganisms are unable to grow. In addition, honey contains very little water in its natural state, preventing bacteria from flourishing.
Which choice gives a second supporting example that is most similar to the example already in the sentence?
A. NO CHANGE
B. Molasses is a byproduct of cane sugar and has an exceptionally long shelf life.
C. Honey may cause bacterial infections in people with weakened immune systems.
D. Fructose and glucose are responsible for honey’s sweet taste.
Solution: The correct answer must provide an example of how honey’s composition allows the substance to stay fresh. Option B is off-topic. The first sentence it makes clear that the paragraph is about honey, not molasses.
Choice C is off-topic as well, but less directly. The correct answer must focus on the characteristics of honey itself, whereas C focuses on honey’s effect on people. So, C is out. The correct answer must explain why honey does not spoil. Sweetness has nothing to do with that fact. Therefore D is not the answer either.
That leaves us with A, which is the answer. Logically, bacteria would cause honey to spoil. The absence of water would prevent bacteria from flourishing, thus keeping honey fresh.
The next common thing you’ll be asked to do on a command of evidence question is to choose the answer choice that best sums up some information presented in the passage.
1. Paragraph Summary - To answer these questions, you have first to summarize the paragraph in your own words. Once you know what the paragraph is about, the answer choice that most specifically talks about the main point of the paragraph is the right answer!
2. Introductory Sentence - When choosing an introductory sentence for a passage, even if this is the first question of the set, don’t answer without first reading the entire passage! Discerning between answer options obviously requires you to know what the passage talks about in each of its sections, so read the entire passage first before picking the best opening line.
3. Concluding Sentence - Choosing a sentence to end a passage is much like choosing one to begin it, except instead of taking into account what’s going to be said, you have to take into account what has been said. Both question types require understanding of the passage as a whole.
The Ashmolean museum is home to works of art from across the centuries. New exhibits from all time periods are regularly featured in the museum; ancient and modern art alike are prominently displayed in the museum’s galleries. It is clear that the Ashmolean is very popular among the local university students.
Which choice provides the best summary of the paragraph?
A. NO CHANGE
B. has been around for a long time.
C. is going to stop opening so many new exhibits soon.
D. values a wide variety of artworks.
Solutions: Answer choices A, B, and C don’t talk about the museum displaying lots of artwork, so they don’t match the main point of the passage. Answer D sums up the main point of the paragraph, so D is the best answer.
The earliest recorded use comes from Sumerian clay tablets, which indicate that honey was used in more than a quarter of all prescriptions. The ancient Greeks and Egyptians also used honey regularly in ointments for skin and eye diseases. Locally produced honey can be an effective treatment for seasonal allergies. The medical device company Derma Sciences sells MediHoney, bandages covered in honey, to hospitals in over 25 countries. In fact, honey has been shown to prevent the growth of foodborne pathogens such as E. coli.
Which of the following provides the best introduction to the paragraph?
A. The carbohydrates in honey can easily be converted to energy because the body quickly digests this natural substance.
B. As a result of this quality, along with a thickness that prevents wounds from becoming infected, honey has been used for medicinal purposes for centuries.
C. In contrast to other sweeteners such as sugar, honey contains a number of vitamins and minerals.
D. Some studies have found that honey can also raise blood sugar levels, but more slowly and by smaller amounts than other sweeteners do.
Solutions: Although this question asks about the introduction, you cannot answer it until you know what the rest of the paragraph is about. If we had to sum up the paragraph above, we might say something like “medical uses of honey,” or “honey = medicine.” B is the only answer that mentions that idea, and it’s almost exactly what our summary says. So, it’s correct.
3. Setting up
The ACT likes to ask us which sentences best “set up” an idea. For the ACT, something that “sets up” the next part of a passage is something that makes that next part the clearest and unsurprising. That means we want to pick phrases that are closely connected to and help explain the information immediately after them.
Fortunately, a new group of artists has discovered the murals, and efforts are underway to clean, restore, and repaint them. Once again, Siqueiros’s “America Tropical” is leading the way. After a lengthy and complex restoration process, this powerful work is now a tourist attraction, complete with a visitor centre and a rooftop viewing platform. Advocates hope that Siqueiros’s mural will once more serve as an inspiration, this time inspiring viewers to save and restore an important cultural and artistic legacy.
Which choice most effectively sets up the information that follows?
A. NO CHANGE
B. being cleaned and restored.
C. at risk of destruction.
D. awaiting its moment of appreciation
Solutions: Choice A, NO CHANGE, is the only answer that makes sense. The paragraph goes on to support the claim that the mural is “leading the way” by discussing its status as the first restored mural to become a prominent tourist destination and inspiration for cultural preservation.
Because philosophy teaches students not what to think but how to think, the age-old discipline offers consistently useful tools for academic and professional achievement.  A 1994 survey concluded that only 18 percent of American colleges required at least one philosophy course. Therefore, between 1992 and 1996, more than 400 independent philosophy departments were eliminated from institutions.
Which choice most effectively if inserted at point  will set up the information that follows?
A. Consequently, philosophy students have been receiving an increasing number of job offers.
B. Therefore, because of this evidence, colleges increased their offerings in philosophy.
C. Notwithstanding the attractiveness of this course of study, students have resisted majoring in philosophy
D. However, despite its many utilitarian benefits, colleges have not always supported the study of philosophy.
Solutions: After reading the final two sentences, we can determine that the information demonstrates that colleges haven’t supported the study of philosophy or shown that they care about philosophy. We need to find a sentence that logically connects to this information. Answer choice D is correct because it sets up the facts that a low percentage of colleges required philosophy and that 400 philosophy departments were eliminated.
The carbohydrates in honey can be converted to energy because the body easily digests this natural substance. The earliest recorded use comes from Sumerian clay tablets, which indicate that honey was used in numerous remedies. The ancient Greeks and Egyptians also used medicinal honey regularly in ointments for skin and eye diseases.  Raw, locally produced honey can be an effective treatment for seasonal allergies. The medical device company Derma Sciences sells MediHoney, bandages covered in honey, to hospitals in over 25 countries.
4. Author’s Goal
These questions ask you to determine if a sentence or phrase fulfills the author’s stated purpose. The following is the strategy to answer the Author’s Goal questions:
A. Determine what the Question is asking you.
B. Go through the answer choices to see if the phrase fulfills the stated purpose. The title of the passage often gives you the best hint to the purpose of a passage.
C. Eliminate wrong answer choices
D. Consider the conciseness, tone, and formality of answer choices, if necessary.
By nightfall a controlled inferno roars in the kiln.
The writer would like to indicate that at this point the fire is extremely intense. Given that all the choices are true, which one best accomplishes the writer’s goal?
A. NO CHANGE
B. the fire is stronger than ever
C. there is more heat being produced
D. a kind of intense blaze takes place
Solutions: The correct answer choice will make it obvious to the reader that the fire is extremely intense. An inferno is a large, intense fire. And the verb “roars” further indicates that the fire is extremely intense. The answer is A, no change.
Solved Long Passage: Tourism vs. Preservation in the Lascaux Caves
Should historical monuments be completely open for the public to examine, or is there greater value in  protecting them for everyone? While many people are willing to travel thousands of miles to view ancient works of art and architecture up close and in person, the more visitors an ancient site has, the more quickly it  crumbles. The history of the Lascaux caves in France attests to this fact. Discovered by accident in 1940, the caves are covered in breathtaking Paleolithic artwork portraying a wide variety of animals in motion. Visitors poured into the site as it  got really popular, but such a high rate of tourism has damaged the art, causing chemical changes as well as  the introduction of lichen and black mold, as well as other deposits. Over interaction with the caves has turned them from a fascinating tourist destination into a world wonder desperately in need of help.  If you want to experience the beauty of the Lascaux caves, visiting the replica site Lascaux II can help you have the experience of exploring the caves without damaging their fragile art.
1. The author wants to emphasize that the historical sites being discussed are areas of potential academic interest. Which of the following choices best accomplishes this?
A. NO CHANGE
B. safeguarding them for future studies
C. shielding them from thoughtless damage and vandalism
D. defending them against artistic criticis
2. Which of the following best encompasses both two-dimensional works of art as well as three-dimensional works of art and architecture?
A. NO CHANGE
3. The author wants to introduce the Lascaux caves as an example of a historic site that has been damaged. Which of the following sentences best accomplishes this?
A. NO CHANGE
B. You may think this isn’t true, but the Lascaux caves prove it is.
C. Works of art like those found in the Lascaux caves form the most important type of historic site to protect.
D. The Lascaux caves show just how selfish some people can be.
4. The author wants to maintain a formal tone throughout the passage. Which of the following options best accomplishes this?
A. NO CHANGE
B. blew up
C. grew in renown
D. became infamous
5. Which of the following best conveys the author’s distaste for the lichen and black mold?
A. NO CHANGE
6. The author wants to end the passage with a call to action. Which of the following sentences best accomplishes this?
A. NO CHANGE
B. Who knows what other sites have yet to be discovered and potentially better preserved?
C. We should learn from what has happened to the Lascaux caves and be content to appreciate unique historic sites from afar so as not to damage them.
D. Scientists hope to eventually restore Lascaux caves to the condition in which they were initially discovered, but this will take a great deal of time and effort to fix a problem that could have been avoided.
1. We’re told that the author wants to emphasize the sites as being of potential interest to academia, so a change might be necessary to achieve that goal. After all, “protecting them for everyone” doesn’t suggest an academic focus – it’s a general phrase. The best answer is “safeguarding them for future studies.” This phrase suggests that in the future, people might be interested in studying sites like the Lascaux caves. B is the correct answer.
2. The distinction here is one of logical reference: we need to pick out the term that best refers to two-dimensional and three-dimensional works. “Deteriorates” is the best answer. A painting can “deteriorate” just as a building can because the word is so general in its meaning. D is the correct answer
3. The author’s goal is to introduce the caves as an example of a historic site that has been damaged. Answer choice A restates the previous point and claims that it is indeed damaged. The correct answer is A.
4. This time, we’re looking for the answer choice that most helps give the passage a formal tone. C is the correct answer; “grew in renown” elevates the formality of the passage’s tone while retaining the same meaning as “got really popular.”
5. We’re looking for the answer choice that best demonstrates “the author’s distaste for the lichen and black mold,” so we’re most likely going to be looking for a negative word. An “infestation” is never a good thing. You wouldn’t refer to an “infestation” of positively-connoted things. C is the correct answer.
6. The author is looking to end his or her passage with a “call to action.” C is the best answer, as it provides a recommendation as to what everyone should do in lieu of recognizing the damage that people have caused by visiting Lascaux. The “should” is a major clue that a recommendation is being given.