求教牛人，渴望指点

这个题实在不明白，请高人给详细指点一下：

In the past year, there has been a large drop in the number of new cars sold, due to harsh economic conditions in the marketplace and high taxes. At the same time, the average price paid for a new car has risen dramatically.

Which of the following, if true, best explains the increase in the average price of a new car?

(A) The price of used cars has climbed steadily over the past ten years.

(B) There will be a tax reduction later in the year which is expected to aid moderate and low income families.

(C) The market for expensive car has been unaffected by the current economic conditions.

(D) Economic conditions are expected to get significantly worse before the end of the year.（C）

(E) Low demand for trucks and vans has led to lower production in the factories.

为什么选C

我也想了好久才想出来的：

注意理解最后一句话“the average price paid for a new car has risen dramatically”。新车的销售量明明因为经济萧条和高税收大大减少了，为什么新车的价格还会急剧上升呢？这分明是有悖常理的，因此要注意“average price”,只有一种可能会导致平均价格升高，那就是售出的高档车在所有售出的新车中比例高了。也可以这样解释就是高档车市场没有受经济因素的影响，保持着以往的销售量，而中低档车市场则因为中低收入者受经济影响大大缩水。总的销售量少了，贵车的数量没有少，造成新车平均售价部将反升的现象。（c）正好说明这种现象。

我发现很多平均值升高或降低的题，不一定是直观的升高降低，有可能是其他原因导致的相对升高或降低。ets太狡猾了。

另外还可以考虑排除法，首先可以排除无关项d、e，然后看选项a，旧车价格不断攀升，则对新车销售不能形成竞争，只能使新车卖得更好；而且旧车价格年年涨，为什么以前新车不涨价，反而是去年新车销量不好了价格倒涨了，不合理啊，可以排除a了；选项b，文中没有说明中低收入家庭是新车的主要消费群体，即使年底有减税，也为必能刺激该群体购车，况且没有说明新车价格的涨幅和税率的减幅，无法判断该群体的购买力，b也可排除了。这样就只剩下选项c了。