A recent university study indicated that students who receive full scholarships tendto maintain higher grade point averages than do students who must take out loans or work to get to finance school. The study concluded that scholarships enable students to achieve high grade point average by alleviating the stress related to financial concerns and freeing up students' time to study more. The study's conclusion depends on which of the following assumptions?
High grade point averages were not the primary criterion upon which the scholarship awards were based.
The evidence of the study indicates that students on full scholarships maintain higher grade point averages (GPAs) than do students who work or take out loans. From this evidence, the study concluded that the scholarships "enable” those students to earn higher GPAs by alleviating financial stress and freeing up the students' time. Notice how the evidence links scholarships and higher GPAs, but the conclusion jumps into the realm ofcause and effect. The word enable is your clue that the author is now speaking of a casual mechanism.
The author assumes that the only possible reason for the association in the casual mechanism cited in the conclusion, and the correct answer will likely bolster this notion by eliminating an alternative explanation. Choice (d) hits on the right issue. It's possible that the author of this argument got the casual mechanism backwards. She agrees that scholarships lead to high GPA's, but may be the opposite is true: high GPA's lead to scholarships. The argument won't work if there's another reason for the correlation cited in the evidence. If high GPAs are the primary criterion for the scholarships in the first place, then it's not surprising that scholarship holders tend to earn higher GPAs than others. The students must generally be of otherwise equal ability before the conclusion can safely be drawn. (d) is the answer because it eliminates a very plausible alternative explanation for the correlation cited in the first sentence, and this is the assumption cited in the first sentence, and thus is the assumption on which this conclusion depends.