– I rang you at about ten o’clock, but there was no reply.
– Oh, that was probably I was seeing the doctor.
A. when
B. why
C. what
D. that
网友回答
(答案→)A. when
B. why
C. what
D. that
解析：考查表语从句：表语从句部分I was seeing the doctor.不缺主宾表， 说明不能用what，根据句意：--10点我打电话给你，但没人接。--那可能是我去看医生的时候。选A。