[讨论]大全I-2

Civic Leader: The high cancer rate among our citizens is the result of hazardous material produced at your plant.

Board of Directors: Our statistics show that rates of cancer are high throughout the valley in which the plant is situated because local wells that    supply drinking water are polluted, not because of the plant.

Which of the following, if true, most seriously weakens the board’s claims?

(A) The statistics do not differentiate between types of cancer.

(B) Nearby communities have not changed the sources of their drinking water.  

(C) Cancer-causing chemicals used at the plant are discharged into a nearby river and find their way into local wells.

(D) The plant both uses and produces chemicals that have been shown to cause cancer.

(E) Some of the pollutants cited by the board as contaminating the local wells have been present in the wells for decades.

之前错选了B，后来发现B是无关选项，因为Nearby的情况怎么样与当地怎么样是没有关系的。

关于答案C有一点想不太通，

C是否定了原来的推理关系中的原因吗？Board的推理是rates of cancers高是因为wells被污染了，而C是说用于plants的chemical污染了wells

恳请牛牛指正！

论原因

Civic Leader：hazardous material produced at plant→high cancer

Board of Directors：local wells that  supply drinking water are polluted→high cancer rate

C选项hazardous material produced at plant→local wells that supply drinking water are polluted

不久成功weaken了吗 说到底还是如civic leader所述