When drive-ins were at the height of their popularity in the late 1950’s, some 4,000 existed in the United States, but today there are less than one-quarter that many.

A.      there are less than one-quarter that many

B.       tnhere are fewer than one-quarter as many

C.      there are fewer than one-quarter of that amount

D.      the number is less than one-quarter the amount

E.       it is less than one-quarter of that amount

 答案选C

我选了E

不能用it指代前面提到的概念，一般用that和those

本来我也想选D，后来发现，前面提到的some 4,000 existed 强调的是个体概念，而D中 the number 强调是整体概念，整体不对应个体。

C中one-quarter of that amount是指4000的1/4