i thought that option B seems to be more parallel still not able to understand why option A is correct
Have you read the explanation by rkanthilal quoted in the posting above?
It is true that B is closer in the way that it is written. But that is not what parallel reasoning is about. It requires you to chose the choice that uses the same logic. In the posts above someone indicates that on parallel reasoning the premises must be in the same order. As I explained in an above post on this thread this is not true. It is the logic that must be the same not the order in which it is written.
B is pretty much valid, whereas the stimulus is not -- so B cannot be the correct answer. Look at B, we are told that "Studies show that large dogs lives shorter lives, on average, than small dogs do." So we must accept this as a fact. Now B continues on to logically apply this by stating that the smaller dog "MIGHT BE EXPECTED" to live longer. This is a proper use of that study. Notice the conclusion does not say that the smaller dog WILL LIVE LONGER, or that if he does live longer that he must have been smaller. Do you see how B is an appropriate use of statistics?
The stimulus is an inappropriate use of statistics. The first statement is similar, "Studies show that children who watch too much television are more likely than others to become obese adults." But now the use that is made of this is too strong. It says that because one person is obese and the other is not, the obese one MUST HAVE watched more tv as a child. Notice the "MUST HAVE" that makes the stimulus invalid. You cannot overgeneralize from "more likely" to a "must have."
So the stimulus is very different from B in the conclusion it draws. B is basically valid, the stimulus is an over-generalization.
Hope that helps!












