During one of her TV shows, Oprah states, "I'm always having trouble with my weight...I'd give a trillion dollars for the secret of staying then. "Buford wrote Oprah a letter saying, "The secret to staying then is to eat less and exercise more. You owe me one trillion dollars." Is Buford entitled to one trillion dollars?

Yes, because he made a proper acceptance of Oprah's offer.

No, because his advice was too well-known to be considered an acceptance.

No, because a reasonable person would have realized that Oprah's offer was not made seriously.

No, because according to the "mailbox rule," this was not a valid method of acceptance.