请教一道LSAT题

swang17

请教一道LSAT题：
7. Politician: Now that we are finally cleaning up the industrial pollution in the bay, we must start making the bay more accessible to the public for recreational purposes. Reporter: But if we increase public access to the bay, it will soon become polluted again. Politician: Not true. The public did not have access to the bay, and it got polluted. Therefore, if and when the public is given access to the bay, it will not get polluted.

Which one of the following most closely parallels the flawed pattern of reasoning in the politician's reply to the reporter?

(A) If there had been a full moon last night, the tide would be higher than usual today. Since the tide is no higher than usual, there must not have been a full moon last night.

(B) The detective said that whoever stole the money would be spending it conspicuously by now. Jones is spending money conspicuously, so he must be the thief.

(C) When prisoners convicted of especially violent crimes were kept in solitary confinement, violence in the prisons increased. Therefore, violence in the prisons will not increase if such prisoners are allowed to mix with fellow prisoners.

(D) To get a driver's license, one must pass a written test. Smith passed the written test, so she must have gotten a driver's license.

(E) In order to like abstract art, you have to understand it. Therefore, in order to understand abstract art, you have to like it.

为什么答案是C而不是A呢？ 这类题应该怎么做才正确和快呢？解题思路应该如何呢？非常感谢！！！

Louisa_xy

题干里：
The public did not have access to the bay, and it got polluted. Therefore,
if and when the public is given access to the bay, it will not get polluted.
结论是premise的否命题。A事件发生，B事件也发生；A事件没有发生，B事件也没有发生。

A)选项是逆否命题。A事件发生，B事件也发生；B事件没有发生，所以A事件也没有发生。

前几天在逻辑版里看到一片逻辑错误类型的帖子，好像是Stephen的....(名字没记住），做过一些逻辑题后再看很有帮助。