Purpose of proving grounds: Designed to be so demanding that only those students most committed to being science majors will receive passing grades in these courses.
C: Designing introductory science courses to serve as proving grounds has not served its intended purpose
Premise: Studies show that some of the students in these very demanding intro courses who are least enthusiastic about science receive passing grades in these courses.
There is a gap here between "most committed to being majors" and "least enthusiastic about science."
What if those who are least enthusiastic are most committed to being science majors and passed the course? That would destroy the author's argument because the sole premise now becomes irrelevant.
However, I feel D is more like a sufficient assumption rather than necessary assumption. Let's negate D : some of the students who are least enthusiastic are among the students most committed to being science majors. However, with this negation, there are still two possibilities: (1) least enthusiastic +most committed + passed the course; (2) least enthusiastic + most committed+ not passed the course. So if all the students mentioned in D fall within the second the possibility, the conclusion still stands. So could anyone explain why D is a necessary one as it is broader than what we need.
Comments
@lschoolgo
P1 Certain introductory undergraduate science courses are designed to be so demanding that only students most committed to being science majors will pass the class.
P2 some students (who are least enthusiastic about science) slip through the cracks and pass the class.
Conclusion: Designing the courses this way (because some students -other than- the most committed ones slip by and pass) fails to achieve its goal of allowing only the most committed ones.
For this NA question we are going to try to help the argument by preventing a counter argument. Let’s say an opponent to this argument says, “Oh yes the design works…some of the same students who are least enthusiastic are also still most –committed- to being science majors.” (Maybe there is a good paying job awaiting them when they graduate)
(D) comes along and says: “None of the students in the very demanding classes (who are least enthusiastic about science are among the students most committed to being science majors. “ This is unstated would be necessary should the argument hold.
If one who was the least enthusiastic was also among the most committed, then the conclusion is destroyed. Why? Because the author is saying the courses are failing at fufilling their purpose because Karen has passed and she isn't enthusiastic. But, if Karen is among the most committed, then it doesn't matter that she's least enthusiastic and we have no basis for saying that the courses are not fufilling their purpose.
Q.E.D.
Some necessary assumption answer choices can be extreme. The stimulus just has to have the extreme language to back it up.