My first O8 question

[goofball]

hero is in the BB with A[img]/images/graemlins/heart.gif[/img] 8[img]/images/graemlins/spade.gif[/img] 2[img]/images/graemlins/diamond.gif[/img] 6[img]/images/graemlins/diamond.gif[/img]

preflop: MP limps, poster in the CO raises, SB and hero call, MP call.

flop is 7[img]/images/graemlins/club.gif[/img] 3[img]/images/graemlins/spade.gif[/img] T[img]/images/graemlins/spade.gif[/img]

SB checks, hero bets, MP calls, CO raises, Hero 3bets, MP folds, CO calls.

turn is 9c

hero bets, CO calls

river is 3h

hero bets?