Only seven people this century have been killed by the great white shark, the man-eater of the movies—less than those killed by bee stings.

E.
movies, fewer than the ones

A错的原因是less不能修饰可数名词？可是B没有those怎么会对呢？少了比较对象啊。

关于可数不可数的修饰和指代不明白，请指教

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.

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

C中的amount不也应该指代不可数名词的吗？