关于白勇语法中的一题

白勇语法中第５题：

While some propose to combat widespread illeagal copying of computer programs by attempting

to change people's attituades toward pirating,others by suggesting reducing software prices to decrease the incentive

for pirating, and still others by calling for the prosecution of those who copy software illegally.

B. by suggesting the reduction.....

C.suggest the reduction of software prices for decreasing the incentive for pirating,and still others call

D.suggest the reduction of software prices to decrease  the incentive for pirating,and still others by calling

E.suggest  reducting  software prices to  decrease  the incentive for pirating,and still others are calling(?)

The answer is E.

请问牛牛们，ＡＮＤ　相连的上下部分应该是平行的，为什么答案Ｅ最后部分的语态可以和前面不同呢？

谢谢！

请问版主,是第几题呢?

谢谢!