SC931. 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

I thought that answer will be either C or D. But the answer is E. Please explain.