[Closed] [NL50 FR Rush] 77 flops set, river play.

Hand converted with online PokerStrategy.com hand converter:

Play hand

$0.25/$0.5 No-Limit Hold'em (9 handed)

Known players:
[tg]BU$18.00:///////;SB$33.95:///////;BB$22.65:///////;UTG1$135.40:///////;UTG2 (Hero)$56.05:///////;MP1$59.85:///////;MP2$60.40:///////;MP3$93.30:///////;CO$86.70:///////;[/tg]

Preflop: Hero is UTG2 with 7:s, 7:c.
UTG1 raises to $1.75, Hero calls $1.75, MP1 folds, MP2 calls $1.75, MP3 folds, CO calls $1.75, BU folds, SB calls $1.50, BB folds.

Flop: ($9.25) 8:d, 7:d, 9:s (5 players)
SB checks, UTG1 checks, Hero bets $6.00, MP2 folds, CO calls $6.00, SB folds, UTG1 folds.

Turn: ($21.25) 3:h (2 players)
Hero bets $13.00, CO calls $13.00.

River: ($47.25) 2:d (2 players)
Hero checks, CO checks.

Final Pot: $47.25.

What should my plan be on river?