A、She was afraid she might be kept too late. B、She would have something more important to do. C、She had to meet a friend of hers

M: I think twice about taking a history class next year. There’s not a single good professor in the whole history department.
W: Look, that’s what you said last semester about the sociology department, and I’m very glad I didn’t pay any attention to What you said.
Q: What does the woman mean?

W: Hello, Kevin. This is Lucy. I’m afraid I won’t be able to attend the party. I was just asked to go to a meeting at the same time as the party.
M: Do come after your meeting, Lucy. Our party won’t be over until midnight.
Q: Why does the woman say that she could not attend the party?