1st hand KK B&M tournament

[ZootMurph]

$500+$60 tournament. 88 players. 5000 starting chips. Blinds 25/50. First hand I'm UTG with KK. I raise to 200. One middle position caller, who I've played with before and is tight/solid player... probably holding a big ace, and the BB calls. Flop is Q 3[img]/images/graemlins/diamond.gif[/img]4[img]/images/graemlins/diamond.gif[/img]. BB looks down at his chips, looks at me and notices me watching him, then he checks, I bet 600 into a 625 pot. MP folds, BB goes allin.

I know nothing about BB. What would you do here?

I folded, he didn't show. I took 2nd in the tournament, so I'd like to think I made the right decision.