Which of the Following Can Be Raised as a Defense

Which of the following can be raised as a defense to a claim of defamation?

A) That the Internet service provider was publishing information originating from a third party.
B) That there was a constitutional privilege to comment about the plaintiff who is a public figure and that the statement was made without malice.
C) That there was a conditional privilege to publish a defamatory statement in order to protect a legitimate self-interest.
D) All of these.