Question ID:PT27 S1 Q4 Passage:     In Yasukawa's month-long study of blackbirds, the percentage of smaller birds that survived the duration of the study exceeded the percentage of larger birds that survived.  However, Yasukawa's conclusion that size is a determinant of a blackbird's chances of survival over a month-long period is probably mistaken, since smaller blackbirds are generally younger than larger ones. Stem:Which one of the following, if true, indicates that the criticism of Yasukawa's research is based on a misunderstanding of it? Correct Answer Choice:AChoice A:Yasukawa compared the survival chances of two different species of blackbirds, a larger and a smaller species, rather than of different sizes of birds within one species. Choice B:Yasukawa examined blackbirds in their natural habitat rather than in captivity. Choice C:Yasukawa did not compare the survival chances of blackbirds with those of other kinds of birds. Choice D:Yasukawa noted that the larger blackbirds had more success in fights than did the smaller blackbirds. Choice E:Yasukawa noted that the larger blackbirds tended to have more firmly established social hierarchies than did the smaller blackbirds.