新prep1-181题

The number of people flying first class on domestic flights rose sharply in 1990, doubling the increase of the previous year. 

A. doubling the increase of

B. doubling that of the increase in

C. double as much as the increase of

D. twice as many as the increase in

E. twice as many as the increase of

答案是A

为什么其他选项不对？多谢了

在语法区search了一下，用baidu也search了一下，没找到，请指导一下，谢谢。