AKs flops a FD, facing aggression on c-bet

[XHitman014]

What is the standard line here?

I have no read on the villian...only seen about 10 hands but at the time but he seemed competent for NL50...this type of aggression usually doesn't mean set but I'm not sure where I stand here. Against an aggressive 2+2-type player I would insta-push but I'm not sure what to do against an unknown who I may not have any FE.

Full Tilt Poker - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 5 Players - (LegoPoker HH Converter)

SB: $62.20
BB: $40.70
Hero (UTG): $50.00
CO: $58.45
BTN: $56.00

Preflop: Hero is dealt A[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/club.gif[/img] (5 Players)
<font color="red">Hero raises to $1.75</font>, CO folds, BTN calls $1.75, 2 folds

Flop: ($4.25) 5[img]/images/graemlins/club.gif[/img] T[img]/images/graemlins/club.gif[/img] 6[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $3.00</font>, <font color="red">BTN raises to $10.00</font>, <font color="red">Hero...