—Yes. But for your help, it________a serious loss.

A. would cause B. must have caused

C. would have caused D. may cause

【答案】C

【解析】考查虚拟语气。答句第二句为含蓄条件句，but for引出虚拟条件，此处表示对过去情况的虚拟，故句子谓语形式为would/should/could/might have done。根据句意可知选C。