请教nn一道语法题...谢谢:)(大全791)

vict2006

The number of undergraduate degrees in engineering awarded by colleges and universities in the United States increased by more than twice from 1978 to 1985.

A increased by more than twice

B increased more than two times

C more than doubled

D was more than doubled

Ehad more than doubled

答案c是不是少了be动词啊？，还有b为什么错了

遥远的绿洲

我已经帮你在标题上补上了题目出处,下次发贴请自己加上题目得出处,谢谢配合