单选题 She ought not ______ him about the truth, but she did.
A. to tell B. telling C. to have told D. having told

【正确答案】 C

【答案解析】[解析] 句子的大意为：她不应该告诉他事实，但是她却告诉了。ought not to have done=shouldn't have done本不应该做某事，但实际上做了。所以C项符合题意。