C, in a private exam room. Telling someone in the waiting room is a clear violation of HIPAA laws, and you're skirting the line at the discharge window. There are too many inherent risks with email: the account on file may be an account multiple people can access; you might have the wrong address, even if due to a typo; and so on. Discussing care in an exam room is the best way to maintain HIPAA compliancy.
