—I regret you that your application has not been successful.—Not successful? I performed

—I regret you that your application has not been successful.
—Not successful? I performed pretty well in my interview!
A. informing
B. to inform
C. having informed
D. to have informed

A. informing(答案→)B. to informC. having informedD. to have informed解析：B　考查非谓语动词作宾语。句意：“我很遗憾地通知你你的申请没有成功。”“没成功？在面试中我表现得很出色呀！”当某一动作在regret之后发生时，regret后需加to do作宾语；当某一动作在regret之前发生时，regret后需加doing/having done/to have done作宾语。本句中inform后于regret发生，故选B。

回答的不错