Because the Academy of Pediatrics recommends that teenagers sleep until around 8 am, claiming that their doing so is beneficial for both their academic performance and overall health, Danterton High School moved its start time from 7:30 am to 9:00 am. However, neither improvement in academic performance nor improvement in health was observed in most students. Clearly, waking up later does not really help teenagers.
In evaluating the argument, it would be most useful to establish which of the following?
Whether most students at Danterton High School prefer the new start time or the previous start time
Whether parents of students at Danterton High School have difficulty getting to work on time as a result of the later start time
Whether most teenagers wake up later than 8 am on weekends
Whether most students at Danterton high school have taken advantage of the new start time by starting to go to morning programs before going to school
Whether improving the diets of students at Danterton High School would be beneficial for both their academic performance and overall health

Solution:
Breakdown of the Argument:
Background: The Academy of Pediatrics recommends that teenagers sleep until around 8 am, claiming that their doing so is beneficial for academic performance and health.
Premise: Danterton High School moved its start time from 7:30 am to 9 am.
Premise: The academic performance and health of the students did not improve.
Conclusion: Waking up later does not really help teenagers.
If this were an Assumption question, we would be looking for an answer that states an assumption integral to the argument. For instance, the argument depends on the assumption that moving the start time has resulted in students’ sleeping until 8 am. Since this is, however, an Evaluate the Argument question, we are instead looking for a different kind of choice, one that asks a question the answer to which is information that either shows that a key assumption is incorrect, and thus weakens the argument, or confirms something that has been assumed, and thus strengthens the argument.
(A) Whether most students at Danterton High School prefer the new start time or the previous start time
We don’t have to assume that the students prefer one start time or another to make this argument. The conclusion is based on the lack of change in academic performance and health. Even if, for instance, students prefer the new time, changing the start time to give the students more time to sleep has not had the expected benefits.
(B) Whether parents of students at Danterton High School have difficulty getting to work on time as a result of the later start time
No matter how we answer this question, the answer doesn’t affect the argument. Regardless of whether the parents are experiencing difficulties as a result of the school’s starting later, changing the start time has not had the expected results, and so the conclusion holds.
(C) Whether most teenagers wake up later than 8 am on weekends
Information on what time teenagers wake up on weekends does not affect this argument. The evidence presented is the apparent lack of results of the change made to the school’s start time. A necessary assumption would link that evidence with the conclusion. Without reason to believe that there is a connection between the time the teenagers wake up on weekends and the school’s start time, there is no clear reason to assume anything about when teenagers wake up on weekends.
CORRECT ANSWER(D) Whether most students at Danterton high school have taken advantage of the new start time by starting to go to morning programs before going to school
To choose this choice, we have to see that the answer to the question that it poses could seriously weaken the argument. The conclusion relies on the assumption that the students are sleeping later because the school’s start time has been changed. However, if the answer to this question is “Yes,” then students aren’t actually sleeping later as a result of the new start time. Rather, they are getting up early to go to morning programs. In that case, the conclusion is based on a faulty assumption and, thus, may not be valid. So, to evaluate this argument, we would want to know the answer to this question.
(E) Whether improving the diets of students at Danterton High School would be beneficial for both their academic performance and overall health
Information regarding whether improving students’ diets would be beneficial for their academic performance and overall health does not help us to evaluate the conclusion that waking up later does not help teenagers.