While the Veto Is Regarded as One of the President's

While the veto is regarded as one of the president's most formidable powers,it is used relatively rarely.This is likely because:

A) most legislation passed by Congress is very important and presidents dare not veto it
B) legislators will alter the content of a bill to make it more to a president's liking in order to preempt a veto
C) legislators have a great deal of certainty about the president's policy preferences
D) one party almost always controls both chambers of Congress and the presidency,so vetoes are rarely necessary
E) presidents are limited in the number of times they can use the veto in a session of Congress