A、The advertisements let us know the best product. B、The advertisements give us sufficient information. C、The advertisements fai

W: Why is there a big sign on the back of your door that says "keys"?
M: It’s to remind me to take my keys when I go out because I’m always locking myself out by accident! It doesn’t help though. Now I just forget to read the sign.
Q: Why is there a sign on the back of the door?

M: Advertisements provide information that we need.
W: Do they? I don’t think so. Every manufacturer says that his product is the best or at least tries to give that impression. Only one can be the best, so others are misleading, aren’t they?
Q:What can be inferred from the woman’s answer?