（ ）your letter of March 5, we are pleased to inform you that the

（ ）your letter of March 5, we are pleased to inform you that the L/C has been received.
A、Replying to
B、Replying for
C、Replied to
D、Replied for
【正确答案】：A
【题目解析】：reply + to 固定搭配：应对。reply 放在句首使用ing形式。