Decision/Newcomb

Newcomb's Problem

A being put one thousand dollars in box A and either zero or one million dollars in box B and presents you with two choices:
(1) Open box B only.
(2) Open both box A and B.
The being put money in box B only if it predicted you will choose option (1). The being put nothing in box B if it predicted you will do anything other than choose option (1) (including choosing option (2), flipping a coin, etc.).

Assuming that you have never known the being to be wrong in predicting your actions, which option should you choose to maximize the amount of money you get?