Complete Question Explanation
"Most Strongly Supported" questions are a subset of Must Be True questions. The correct answers do not always have to be true, but they are the answers that have the most support from the stimulus. These can be looked at as reverse strengthen questions, where the stimulus provides the most support for one of the answers, and less (or no) support for the four incorrect answers. As with strengthen questions, we do not have to prove one of the answers, just help it more than we help the others. Students who treat these as strict Must Be True questions may find themselves arguing with the correct answer because it doesn't need to be true. You should always avoid arguing with the answers, regardless of the question type, because you are never looking for perfect answers but always and only the "best" answer from among those provided. This is especially true in the case of Most Strongly Supported questions like this one.
The stimulus sets out that baby macaques imitate humans who make the same sort of gestures that adult macaques make, and they don't imitate those gestures made by humans but not made by adult macaques. We only know about four types of gestures (lip smacking, sticking out tongues, opening and closing mouths, and making hand gestures), so there may be other types of gestures missing from our data set (like nodding or shaking the head, for example). For that reason, we have to be careful not to overstate our case, but since this is Most Strongly Supported and not pure Must Be True, we could still accept an answer that is broader than our evidence may actually prove.
Answer A: This is an opposite answer, as it appears that it is the least supported choice and may even be a good Cannot Be True answer. Baby macaques don't mimic whatever they see, because they don't mimic humans making hand gestures or opening and closing their mouths.
Answer B: This answer brings in outside information about what baby macaques cannot do and about their muscle coordination. As with any question in the 'Prove" family, new information is not allowed, so this answer must be rejected.
Answer C: As with answer B, this answer brings in new information. The stimulus tells us nothing about why or how adult macaques use these gestures, only that the babies imitate humans who do gestures also done by adult macaques and do not imitate humans doing certain gestures not done by adult macaques. For all we know, it has nothing to do with entertainment and may instead be a form of symbolic communication.
Answer D: Probably the most attractive wrong answer, this one fails for being too speculative about what the baby macaques are thinking. We cannot know, and there is no support for the claim, that the babies are making any mistakes. They may be perfectly aware that humans are not adult macaques, or they may be getting us mixed up with their elders, but the stimulus offers no guidance either way.
Answer E: This is the correct answer. As mentioned previously, we cannot prove this answer is absolutely true, because there may be other gestures that haven't been tested, but at least based on the data we have so far this is the answer with the most support. Out of the four types of gestures tested, the baby macaques only imitated humans when they did gestures also done by adult macaques. Since this is the answer that has the most support from the stimulus, it is the best answer of the bunch, and it is the credited response.