I think he didn’t take a bus yesterday because there aren’t any buses on Sundays.
A. He couldn’t have taken a bus yesterday because there aren’t any buses on Sundays.
B. He mustn’t have taken a bus yesterday because there aren’t any buses on Sundays.
C. He needn’t have taken a bus yesterday because there aren’t any buses on Sundays.
D. He mightn’t have taken a bus yesterday because there aren’t any buses on Sundays.
Ai giải thích câu này hộ mình với :3