optimal river line? top&bottom pair, strange hand

[Irish Mafia]

Don't have villain's stats in front of me. But they were fishy - like 32/8 or something. A non-regular who def. played bad in general. What is the optimal river line?

Full Tilt Poker - No Limit Hold'em Cash Game - $5/$10 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $644.75
BB: $3,109.50
Hero (UTG): $1,184.00
MP: $300.50
CO: $1,807.40
BTN: $1,035.00

Preflop: Hero is dealt 2[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/spade.gif[/img] (6 Players)
<font color="red">Hero raises to $35.00</font>, MP folds, <font color="red">CO raises to $78.00</font>, BTN calls $78.00, 2 folds, Hero calls $43.00

Flop: ($249) 5[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/club.gif[/img] 2[img]/images/graemlins/diamond.gif[/img] (3 Players)
Hero checks, CO checks, BTN checks

Turn: ($249) 7[img]/images/graemlins/diamond.gif[/img] (3 Players)
<font color="red">Hero bets $210.00</font>, CO calls $210.00, BTN folds

River: ($669) K[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero ??
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