Both are correct, but the meanings are totally different. "Have you ever given money to a charity?" is a factual question. The speaker wants to know if the other person has in fact ever given money to charity at any time in their life. "Would you ever give money to a charity?" is a hypothetical question. This is a conditional form, used to imagine a supposed situation. The speaker presumes that the other person has never actually given money to charity. They are asking whether there might potentially be a situation in which the other person would give money.

Answer B, of course. ;)