OG 160

160. While some propose to combat widespread illegal copying of computer programs by attempting to change people's attitudes 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.
(A) by suggesting reducing software prices to decrease the incentive for pirating, and still others by calling
(B) by suggesting the reduction of software prices to decrease the incentive for pirating, and still others call
(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 reducing software prices to decrease the incentive for pirating, and still others are calling

Correct Answer: E

My question: 为什么一般现在时和现在进行时可以形成平行结构 ("propose", "suggest" and "are calling"？难道不是都应该用同样的时态吗？

我觉得这题如果把C 的 for decreasing 改成 to decrease 也是可以选的，正如解释说的 for decreasing is nonidiomatic. 比较起来，还是E 对，因为这里平行的都是现在时。