Hi there, thanks for your post. This is a Parallel Reasoning question.
Let's first examine the reasoning in the stimulus.
First, you are told that two things are correlated (people who studied music as kids frequently are quite proficient at math), but warned that you should not conclude from this correlation that one thing causes the other (that the skills required for math are acquired by studying music). Instead, you are given an alternative possible cause that could account for both effects (it is equally likely that proficiency in math and studying music are both the result of growing up in a family that encourages its children to excel at all intellectual and artistic endeavors).
Answer choice (A) parallels this reasoning. First, you are told two things are correlated (children who fail to pay attention tend to perform poorly in school), but warned that you should not necessarily conclude from this correlation that one thing causes the other (it should not necessarily be thought that their poor performance is caused by their failure to pay attention). Instead, you are given an alternative possible cause that could account for both effects (it is always possible that their failure to pay attention is due to undiagnosed hearing problems that can also lead to poor performance in school).
Hope this helps! Please let us know if you have any additional questions.