Which of the Following Is True About the Liability of an Agent

Which of the following is true about the liability of an agent who has the authority to sign?

A) Under agency law, the principal would be bound by the act of the agent, if the signature is the authorized signature of the principal
B) An authorized signature may be ratified by the principal.
C) A negligent person can assert lack of authority against a holder in due cause.
D) Authorized signatures are not binding.
E) The general rule in agency law is that the agent is liable if he signs his own name making clear he is doing so as an agent.