大全-Ⅰ-17.    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.

答案是c,看不出有任何explain的作用，是不是还需要其他的常识呢？

请指教，谢谢：）

确实看不出选c的原因，请高手指教吧。

价格上升，无非就是收入增加导致的需求上升，或者成本上升，或者供给下降？