选择题：I don’t know why he is late, he might have had an

I don’t know why he is late, he might have had an accident.
A.我不知道他为何迟到，可能遇上了事故。

B.我不知道他为何没有迟到，很有可能遇上了事故。

C.我不知道他为何迟到，一定是遇上了事故。