I vaguely recall that it is the high-beam headlight at half power. However, I am pretty sure it is either the high or low beam, which I believe are both in the same bulb. If you turn on your low beams and see one (or both) out, you have the answer. If not, turn on the high beams and look for one of them out.
Another option would be to wait a few minutes when it is likely that someone with the exact answer will reply.