50NL extraction question

[wslee00]

:: edit - villain is unknown ::

I've been having some trouble extracting these days, so hope you guys can help me out.

pokertracker is acting up on me - so it didn't save the hh - going from memory:

UB - 6 handed 50NL. 100BB eff stacks.
Hero is CO
Villain is UTG
4 other players

Villain calls, one fold, Hero raises to 2.25 with K[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/diamond.gif[/img], BTN calls, Villain calls.

Flop (pot ~7): 5[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/diamond.gif[/img] 8[img]/images/graemlins/diamond.gif[/img]
Villain checks, Hero bets 6.25, one fold, Villain calls.

Turn (pot ~20): 4[img]/images/graemlins/diamond.gif[/img]
Villain bets 8, Hero ???

What do you put villain on and what is the best way to extract?