[求助]一道逻辑题

21. Historian: We can learn about the medical history of individuals through chemical analysis of their hair. It is likely, for example, that Isaac Newton’s psychological problems were due to mercury poisoning; traces of mercury were found in his hair. Analysis is now being done on a lock of Beethoven’s hair. Although no convincing argument has shown that Beethoven ever had a venereal disease, some people hypothesize that venereal disease caused his deafness. Since mercury was commonly ingested in Beethoven’s time to treat venereal disease, if researchers find a trace of mercury in his hair, we can conclude that this hypothesis is correct.

Which one of the following is an assumption on which the historian’s argument depends?

(A) None of the mercury introduced into the body can be eliminated.

(B) Some people in Beethoven’s time did not ingest mercury.

(C) Mercury is an effective treatment for venereal disease.

(D) Mercury poisoning can cause deafness in people with venereal disease.

(E) Beethoven suffered from psychological problems of the same severity as Newton’s.

请教一下怎么分析,谢谢!

mercury  -> psychological problem ->Beethoven must suffer also

E

我现在有点想通了,“an assumption on which the historian’s argument depends”就是如果这个assumption不存在那这个argument就不能得出.B里“Some people in Beethoven’s time did not ingest mercury”这一条如果不成立,也就是如果Beethoven那时候每个人(不管有没有病)都注射了mercury,那即使在Beethoven身上查到了mercury也不能说明他有venereal disease,也就不能说明他的deafness是venereal disease造成的了.这个题目有点搞,开始一直想不通.