[求助]大全336

336.        Ideally, the professional career diplomat should help in the ongoing maintenance of an effective American foreign policy despite changes in administration.

(A) in the ongoing maintenance of

(B) in the maintaining of

(C) maintain

(D) to maintain and continue（C）

(E) the maintenance of

答案是C。我想问一下的是，help中间不加to, 就能直接连接动词吗？

help 后完全可以接不带to的不定式

应该是C