Can you solve the Pinocchio "green hats" logic puzzle?

Here's an interesting logic puzzle from MindYourDecisions:

Assume that both of the following sentences are true:

  • Pinocchio always lies
  • Pinocchio says, "All my hats are green."

What can we conclude from the above two statements:

(A) Pinocchio has at least one hat.
(B) Pinocchio has only one green hat.
(C) Pinocchio has no hats.
(D) Pinocchio has at least one green hat.
(E) Pinocchio has no green hats.