请教ｐｒｅｐ逻辑题

gmatziyu

Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researchers believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40.SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus.Researchers hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.



Which of the following, if true, most strongly supports the researchers' hypothesis?



(A) SV40 is widely used as a research tool in cancer laboratories.

(B) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.

(C) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.

(D) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.

(E) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.

请问这题为什么不是Ｃ呢？
谢谢！

虎宝

我原来做的时候也在想C，不过现在看E最好。
文中让我们加强的是mesotheliomas中的SV40是从vaccine中来的。C选项是再次陈述文中的事实：从1960年后的vaccine中发现了SV40，但是没有和mesotheliomas建立联系。
E选项说vaccine中没有SV40的Finland，mesotheliomas中就没有SV40，建立了联系，说明United States vaccine中的SV40 是造成mesotheliomas中含有SV40的原因。

gmatziyu

你说得很对