GWD-TN-15－1

According to analysts, an alliance between three major personal computer companies and most of the nation’s largest local telephone companies would enable customers to receive internet data over regular telephone lines with speeds much higher than is currently possible.

A.      with speeds much higher than is

B.       with speeds that are much higher than are

C.      at much higher speeds as are

D.      at much higher speeds than that

E.       at speeds much higher than are

问下为何选e，abcd有何错误，e为什么用are啊？请nn们指教

这题不可以选D吗？

一定要补充are吗？不是说不引起歧义就可以不补吗？

究竟是什么时候要补呢？

请教各位，谢谢~