--Beg your pardon please.I didn't quite catch what you said.---Oh I to myself.A. had ta

问题补充：

--Beg your pardon, please.I didn quite catch what you said.---Oh, I to myself.

A. had talked

B. talking

C. talked

D. was talking

答案：

A. had talked

B. talking

C. talked

(答案→)D. was talking

解析：对方没听清楚，请求我把刚才的话再说一次。我答时说：哦，我那时在自言自语啊！说明对方没听清楚的原因。