NL 25 AKs..what does this guy have?

[crushednuts]

Poker Stars - No Limit Hold'em Cash Game - $0.10/$0.25 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $15.45
BB: $41.55
UTG: $29.65
Hero (MP): $27.05
CO: $13.45
BTN: $23.80

Preflop: Hero is dealt K[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/club.gif[/img] (6 Players)
UTG folds, <font color="red">Hero raises to $1.00</font>, 3 folds, BB calls $0.75

Flop: ($2.10) 3[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/diamond.gif[/img] 7[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">BB bets $3.50</font>, Hero ??

villain is 45/5/5 over 45 hands...
I will post the turn once i get some ideas of what you guys think is optimal on the flop