听力原文:M: I kept looking for Mary at the seminar but never did see her. I can't imagine
W: Oh she didn't. It's just that she caught a really bad cold a couple of days ago.
Q: What can be inferred from the conversation?
(17)
A.Mary forgot about the seminar.
B.Mary has been ill for several weeks.
C.Mary wasn't able to attend the seminar.
D.Mary hadn't planned to attend the seminar.