The stimulus here presents an argument, the conclusion of which is "car accidents involving teenagers driving to school could be reduced if the school day began later than 8:00 A.M." The support given for this conclusion is that (1) teenagers tend to wake up around 8:00 A.M., and are sleepy if made to wake up earlier, and (2) sleepiness can impair driving ability. Also given in support of this conclusion is the experience of the town of Granville.
Answer choice (E) supports the argument in the stimulus, albeit in a roundabout way. What if car accidents involving teenage drivers in the region surrounding Granville had also declined during the same period? Then a critic could say, "hey, it's not the later start time that's causing a decline in teenage driving accidents, it's some other cause that is making teenage drivers less likely to get into accidents altogether."
Put differently, answer choice (E) eliminates another possible cause for the perceived effect. It's rather oblique, but nonetheless, this is the right answer.
Hope this helps! Please let us know if you have any additional questions.
hannah93092May 30, 2018
Okay, that's where I was heading but wasn't sure - thanks so much!
