请教一道比较题：SC大全149

149. Last year, land values in most parts of the pinelands rose almost so fast, and in some parts even faster than what they did outside the pinelands.

(A) so fast, and in some parts even faster than what they did

(B) so fast, and in some parts even faster than, those

 (C) as fast, and in some parts even faster than, those

(D) as fast as, and in some parts even faster than, those

 (E) as fast as, and in some parts even faster than what they did

问题是those后面为什么没有助动词？什么时候可以省略啊？

多谢各位！