From today onwards, for a few days, I will post one Bold Faced CR Question.
Unfortunately, I have the OA, but no explanation. So every person who solves the question must give a valid explanation.

Here goes for today:

The interstitial nucleus, a sub-region of the brain’s hypothalamus, is typically smaller for male cats than for female cats. A neurobiologist performed autopsies on male cats who died from disease X, a disease affecting no more than 0.5 percent of male cats, and found that these male cats had interstitial nuclei that were as large as those generally found in female cats. Thus, the size of the interstitial nucleus determines whether or not male cats can contract disease X, but, the hypothalamus is known not to be causally linked to disease Y, and disease X is a subtype of disease Y.

The two portions in boldface play which of the following roles?

(A) The first is a fact in support of the consideration that is one of two points of this argument; the second is the alternative point that weighs against the first.
(B) The first is an evidence that supports the consideration that the argument includes; the second is the fact that weighs against that consideration that could be drawn from the first.
(C) The first is a general principle that is against the conclusion; the second is that conclusion.
(D) The first is an evidence that supports the conclusion; the second is an exceptional example.
(E) The first is a fact in support of the conclusion that the argument depends on; the second is a fact that is against the first one.

Disclosure:
These questions have been taken from a word document found in a forum. But apparently a few have been taken from the OG. Nevertheless, its good practise.
_________________

GMAT done - a mediocre score but I still have a lot of grit in me

The last 20 days of my GMAT journey

I think B is a better answer even though the OA says A. i think this is not a real GMAT question and either it is a badly presented question or badly presented answer choices, since with a real official GMAT logic questions things are very black and white with no possibility of gray areas.

I believe the whole argument has one consideration which starts with a conclusion indicator [thus]: "Thus, the size of the interstitial nucleus determines whether or not male cats can contract disease X", the first bold face: "these male cats had interstitial nuclei that were as large as those generally found in female cats" just supports the consideration. and the 2nd bold face "but, the hypothalamus is known not to be causally linked to disease Y, and disease X is a subtype of disease Y." casts doubt on the consideration.
B) is not saying that the 2nd bold face is drove from first bold face, it is saying that it goes against the consideration that is drove from the first bold face. which is exactly what is going on with the argument. on the other hand

A)says that the argument has two points, which is not correct. argument has one point and two contradicting premises.the 2nd bold face is not an alternating consideration it is just another premiss that goes against the conclusion that the author tries to get too. and if you notice the author says "it CAN cause" and he does not say "it will cause" in the conclusion he gets to, he leaves room for the 2nd bold face to casts its doubt. additionally A says that "

I will go with B. Can someone please explain it more properly..