[問題]Feifei-24

[sa_pot]

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.

ans.E

為什麼不是B呢？

[yphpv]

The key of the question is to prove that the size of interstitial nucleus of male cats has nothing to do with contracting disease X.

Answer B didn't give you any information about the relationship between the size of interstitial nucleus and disease X; it only states the fact that male cats contract disease X and disease Z at the same time, which is irrelvant information in terms of answering the question.

Answer E, however, clearly states:
1. Disease X is a subtype of disease Y
2. Hypothalamus is known not to be causally linked to disease Y.

Hope my explanation makes sense to you.

[yphpv]

請刪除

[yphpv]

請刪除

[dibert8]

(A) 無關於 female
(B) 無關於 disease Z
(C) 無關於 female
(D) 異常率 = 0.5%, 符合命題敘述,沒有弱化
(E) hypothalamus 與 disease Y/X 無因果關聯