费费NO.24请教

24. The interstitial nucleus, a subregion 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 .05 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.

Which one of the following statements, if true, most seriously weakens the argument?

(A) No female cats have been known to contract disease X, which is a subtype of disease Y.

(B) Many male cats who contract disease X also contract disease Z, the cause of which is unknown.

(C) the interstitial nuclei of female cats who contact disease X are larger than those of female cats who do not contract disease X.

(D) Of 1,000 autopsies on male cats who did not contract disease X, 5 revealed interstitial nuclei larger than those of the average male cat.

(E) The hypothalamus is known not to be causally linked to disease Y, and disease X is a subtype of disease Y.  E

Why B is wrong? As B, subtype disearse Y may determine the size of the interstitial nucleus, which weeken the conclusion.

不明白你红字是什么意思。不过这道题目很明确的啊：B项和题目无关啊，题干的结论是讨论的size of interstitial nucleus和接触disease X的关系，B却说到了Z，肯定无关啊。

E明确说了X which is a subtype of disease Y is not causally linked to the hypothalamus.显然weaken了结论啊！