Question

M's statements about it being impossible to find a person between the ages of 85 and 90 who primarily uses the left hand is leading us somewhere. What could possibly be her unstated hypothesis/conclusion? It could be that those who are left-handed do not live as long as those who are right-handed, since their prevalence in old age is scant i.e. that "being born-right handed confers a survival advantage." The question stem is asking you to identify M's hypothesis that M's evidence about 85 to 90 year olds is used to support but that Q's response would serve to counter. So, Q's response provides us with counter evidence that a lack of left handedness in old age is not due to left handedness leading to a shorter life span, but due to children seventy to ninety years ago being punished for using their left hand and, therefore, being forced to use their right hand. Thus, Q's response counters M's unstated hypothesis, which the question stem is asking us to identify, i.e. that being born right-handed confers a survival advantage. Hope that helps! Please let us know if you have any more questions.

Why is D incorrect

Hi @JayDee8732, thanks for your post. Let's first be sure we understand the structure and content of the stimulus. There are two speakers, M and Q. Each one presents you, the reader, with a single fact. Neither reaches a conclusion. The question stem is tricky. It asks you to identify a conclusion that M *COULD* draw, based on M's fact ("It is almost impossible to find a person between the ages of 85 and 90 who primarily uses the left hand."), that Q's fact would COUNTER. Being very clear on this is crucial to getting the right answer. Answer choice (D) is wrong because the fact that Q supplies (that, 70-90 years ago, children used to be punished for using their left hands and were forced to use their right hands) does not in any way address the underlying CAUSE of handedness generally. It certainly doesn't address genetic predisposition, and it's not adequately time-limited to appropriately fit into M's claim re: 85-90-year-olds. The reason answer choice (A) is right is also important. If M were to claim that the fact that there are hardly any left handed people aged 85 to 90 means that being born right-handed confers a survival advantage, Q's counter fact helps to undermine this argument by establishing that many 85 to 90 year olds might have actually been born left handed and trained to use their right hands instead because of social norms. Hope this helps!

I'm really confused by this question. How come answer choice (B) is incorrect?