请教两道削弱题~~在线等答案~~

17. Since 1945 there have been numerous international confrontations as tense as those that precipitated the Second World War, and yet no large-scale conflict has resulted. To explain this, some argue that fear of enormous destruction such as the Second War produced has had a dramatic deterrent effect.

Which of the following, if true, most seriously weakens the deterrent theory mentioned above?

(A) After the First World War, the fear of great future destruction was as intense as it was after the Second World War.

(B) Psychologists have determined that the fear of retaliation tends to temper aggressiveness among human beings.

(C) The Second World War was far less distractive than most people generally believe.

(D) Fear of repeating the levels of destruction that the Second World War produced is as pervasive today as it was forty years ago.

(E) Many of the international confrontations that have occurred since 1945 have involved countries that participated in the Second World War.

 请问为什么不选c

20. The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.

Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

(A)
            Many new water-treatment plants have been built in the last five years in the rural county.

(B)
            Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.

(C)
            Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.

(D)
            Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.

(E)
            The water in the rural county was brought up to the sanitary standards of the water in neighboring counties 10 years ago.

请帮忙解释一下B选项

第一题，题目说因为害怕灾难性的破坏，所以导致了战争没爆发。

A，说二次世界大战，人们都一样害怕破坏性的结果。要是，如题目的逻辑那么人们害怕的话就不会有第二次世界大战了。属于有因无果

C,说二战没有如人们想象的那么有破坏性。这个选项是肯定错的。第一人们所想象的破坏性到底大不大呢？没人知道。第二，要是真的用这句话推出二战的破坏性很小，也只能说明人们到底怕不怕。

第二题题目的意思是因为decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year，所以reduced the incidence of the disease.

C，给出他因。

B的话，得病的跟没得病的人，喝Bottled spring water 的数量差不多。这个跟题目的逻辑根本带不上关系哈。