有段时间做逻辑感觉特好，几乎不错，最近似乎一点感觉都没有了，经常百做百错。不知道是什么原因，我该怎么办哪？下面是一道我没想明白的逻辑题，那位牛牛顺便帮我看看呀，谢谢啦
The U.S. census is not perfect: thousands of Americans probably go uncounted. However, the basic statistical portrait of the nation painted by the census is accurate. Certainly some of the poor go uncounted, particularly the homeless; but some of the rich go uncounted as well, because they are often abroad or traveling between one residence and another.
Which of the following is an assumption on which the argument above depends?
(A) Both the rich and the poor have personal and economic reasons to avoid being counted by the census.
(B) All Americans may reasonably be classified as either poor or rich.
(C) The percentage of poor Americans uncounted by the census is close to the percentage of rich Americans uncounted.
(D) The number of homeless Americans is approximately equal to the number of rich Americans.（C）
(E) The primary purpose of the census is to analyze the economic status of the American population. | 
