GWD-7-Q4，关于a number的指代问题

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.

A.      movies—less than those

B.      movies—fewer than have been

C.      movies, which is less than those

D.      movies, a number lower than the people

E.       movies, fewer than the ones

答案为何不能选D？翻了以前的讨论贴，没有回答这个的

同意B，

D的number和people无法比较