$50.00 No Limit Hold'em - 5 players -
UTG: $55.25
CO: $55.87
Hero (BTN): $50.50
SB: $176.86
BB: $50.75
Pre Flop: ($0.75) Hero is BTN with A

9
2 folds,
Hero raises to $1.25,
1 fold,
BB raises to $4,
Hero raises to $10, BB calls $6
Flop: ($20.25) Q

3

6
(2 players)
BB checks, Hero ???
BB
Villain was 3betting a lot from BB, so I thought A9o could be a good hand to fight back with a bluff 4bet.
I had no notes on what he calls 4bets with. How would you proceed on this flop?