请教一道题...

拾海

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.

(E) The primary purpose of the census is to analyze the economic status of the American population.

答案选C。虽自己也选了C，但后来觉得如果poors的基数很大，riches的基数很小，那整个basic statistical portrait 不就不精确了吗？

望指点...

rickywang

嗯。。感觉B和C一起就更好了。