[mmcd]

AQs, QQ,TT, 99,88.. etc.

You are giving this player FAR too wide a range of hands given the description and the action.

Most of the time he has: AA KK AK AQs JJ. QQ and TT are possible, but I think its unlikely that a solid player leads into 3 opponents with either of these hands.

This situation is far from cut and dry. If he is behind (which is fairly likely here) He's drawing to 0-2 outs and probably has to commit to see a showdown absent an A or a 4-liner hitting the board.

I honestly don't know what the right answer is here as it would depend heavily on the opponent and the way in which he 3-bet and bet the flop.

You are going to be subject to making a mistake here no matter what you do, but folding is not drastically worse than any other course of action.