请教FEIFEI逻辑一道

nymphl

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 disese Y.

为什么B不可以呢，如果X和Y都同时存在，那脑核大部就不能判断有X了么？

谢谢

nymphl

谢谢楼上的回答。

felifeli

B稍微有点削弱，但是没有E 那么seriously weaken吧

B说感染了X的也感染了Z，也就是有可能是其他的因素，但不确定
而E明确说了hypothalamus（也即 interstitial nucleus ）跟Y （也即X）没关系。 直接否定了原文中的结论。