Pretty sure Hater has a set...how much to raise him on the flop?

[QuattroFour4]

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

BB ($31.70)
UTG ($58.50)
MP ($23.65)
Hero ($50.50)
Button : Villain ($101)
SB ($42.90)

Preflop: Hero is CO with 4[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/club.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises to $2.25</font>, Button : Villain calls $2.25, <font color="#666666">1 fold</font>, BB calls $1.75.

Flop: ($7) 8[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, <font color="#CC3333">Hero bets $3</font>, <font color="#CC3333">Villain raises to $10</font>, BB folds, <font color="#CC3333">Hero?