Wrong flaw. (A) arrives at a sweeping conclusion about snacks (that kids buy most of the snacks at cinemas) by pointing out a trend that only pertains to one type of snack (popcorn sales increase as the proportion of child moviegoers increase at a cinema). In the stimulus, meanwhile, the author arrives at a sweeping conclusion about parking citations in university towns by pointing out a trend that pertains to all parking citations in university towns.

Wrong flaw. (B) points out a phenomenon (one plant being greener than another) and then erroneously concludes, without any evidence, that one particular factor (sunlight) must be causing that phenomenon. In the stimulus, meanwhile, the author commits an “assuming correlation proves causation” flaw.

No flaw. (C) points out that most people who attend a university study and, by definition, concludes that most people who go to a university are studious.

Wrong flaw. (D) points out a phenomenon (consumers buying more fruit during the summer than during the winter) and then erroneously concludes, without any evidence, that one particular factor (varieties of fruit) must be causing that phenomenon. In the stimulus, meanwhile, the author commits an “assuming correlation proves causation” flaw.

The argument describes a phenomenon (when other people’s children visit a parent’s house, parents give out more snacks than usual) and arrives at a conclusion that attributes a cause to that phenomenon (most of the snacks parents buy go to other’s children). This commits the same “assuming correlation proves causation” as the stimulus because we have no way of knowing who’s receiving the snacks. We can’t definitively conclude that other people’s kids are receiving the snacks just because parents give out more snacks when other people’s kids are at their house.