There are two keys to getting this question right. One is not getting sucked in by trap answers. The other is noticing that one answer challenges an assumption that the board member made, that the average of the students' scores on state-issued tests has decreased because of increased drug use.
Here's the conclusion. If by incorporating drug use awareness classes into the curriculum at Longview Prep we can reduce drug use, we can increase the averages of Longview Prep students' state-issued test scores to the levels at which they were five years ago.
(A) Students who use drugs the most will not leave Longview Prep and enroll in other schools because they prefer not to attend drug use awareness classes.
While students leaving the school to avoid the classes may somehow seem to hinder the success of the plan, the truth is that if drug use is truly connected to lower test scores, then if the students who use drugs the most were to choose to leave Longview Prep, the averages of Longview Prep students' test scores should increase.
(B) Longview Prep has not over the past five years changed its curriculum by shifting its primary focus from imparting knowledge to the development of critical thinking and research skills.
The board member has assumed that the reason for the lower scores is increased drug use. In other words, the board member has assumed that scores have not declined for some other reason, such as that the school has changed its curriculum in such a way that the curriculum does not match what the state-issued tests test to the degree that the curriculum had in the past. If the students are learning via the use of a new curriculum primarily focused on the development of critical thinking skills, then likely what they are learning is not as applicable to answering questions that appear in state-issued tests of general knowledge than what the students were learning before was.
(C) Longview Prep students who use drugs are not able to hide their use of drugs from teachers and administrators at Longview Prep.
This answer could trap the test taker if the test taker somehow makes an unfounded assumption about a need for signs of drug use to be evident in order for the plan to work.
(D) Test focused review sessions would not be effective in increasing Longview Prep students' state-issued test scores.
The board member's argument does not depend on the assumption that there are not other ways to increase the scores. One way a test taker might choose this answer is by going beyond what can logically be inferred from what is discussed in the prompt.
(E) Most students who use drugs will not eventually reduce their drug use on their own, without having taken drug use awareness classes.
If the test taker is not clear about what's going on in the argument, this answer might be tempting, but the fact that students might eventually reduce drug use on their own does not somehow make drug use awareness classes less effective.
The correct answer is B.