单选题 Woman: I don't think we should have told Tom about the surprise party for Lucy.
Man: It's all right. He promised not to tell, and he doesn't make promises lightly.
Question: What does the man mean?
A. Tom has arranged a surprise party for Lucy.
B. Tom will keep the surprise party a secret.
C. Tom and Lucy have no secrets from each other.
D. Tom didn't make any promise to Lucy.