求助大全244

1.        Dirt roads may evoke the bucolic simplicity of another century, but financially strained townships point out that dirt roads cost twice as much as maintaining paved roads.

(A) dirt roads cost twice as much as maintaining paved roads

(B) dirt roads cost twice as much to maintain as paved roads do

(C) maintaining dirt roads costs twice as much as paved roads do

(D) maintaining dirt roads costs twice as much as it does for paved roads（B）

(E) to maintain dirt roads costs twice as much as for paved roads

为什么D不对?

it只能指代人或物，不能指代maintaining这种动作吧。

答案是B吗？