[求助]GMATPrep上的一道题

For years the beautiful Renaissance building in Palitito have been damaged by exhaust from the many tour buses that come to the city. There has been little parking space, so most buses have idled at the curb during each stop on their tour, and idling produces as much exhust as driving. The city has now provided parking that accomodate a third of the tour buses, so demage to Palitito's buildings from the buses' exhaust will diminish significantly.

Which of the following, if true, most strongly supports the argument?

A) The exhaust from Palitito's few automobiles is not significantly threat to Palitito's buildings.

B) Palitito's Renaissance buildings are not threatened by pollution other than engine exhaust.

C) Tour buses typically spend less than one quater of the time they are in Palitito transporting passengers from one site to another.

D) More tourists come to Palitito by tour bus than by any other single means of transportation.

E) Some of the tour buses that are unable to find parking driving around Parlitito while their passengers are visiting a site.

Answer: C

哪位高人可以解释一下啊？谢谢啦。。。

可能是说在路上driving的时间短（制造的尾气也少）原来大部分尾气是汽车idle的时候排出来的

我一开始选不出来，因为没仔细想C

试着理解一下。P城的文艺复兴建筑饱受尾气之苦，由于停车场少，大多数车只能停在路边，发动机空转，怠速时的尾气排放和行驶时一样，所以P城决定增加停车场，以求减少尾气排放。

推理过程应该是停车场会直接或间接减少尾气的排放。

A与P城本城的车无关

B与其它污染无关（如果问假设，偶选B，排除他因，但现在有没有其它污染与发展停车场是否能减少旅游车的污染无关）

C旅游车在P城运送游客时间少了。答案！其实中间推了两步，偶看完题第一直接的感觉是停车场会与尾气排放减少有关，但没有直接的答案。C是通过说运送游客的时间短了，所以污染少了，中间的一个前提就是题干提供的：无论是在路边怠速空转还是行驶当中，都会有尾气产生，所以C成立。C选项变一下，应该也可以出个评价题。

D与游客来的交通方式无关，题目已经指出是旅游车这个前提了。

E是削弱，找不到停车场的车继续在城里开着转，只会增加尾气的排放。