Villain's not very good, don't think he has much here. I checked the river b/c the K might be scary to him and I want him to take a stab. How much should I raise?

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

Hero ($76.35)
BB ($87.75)
UTG ($50)
MP ($49.50)
CO ($59.60)
Button ($12.60)

Preflop: Hero is SB with T, A.
4 folds, Hero raises to $1.5, BB calls $1.

Flop: ($3) 5, 3, T (2 players)
Hero bets $2, BB calls $2.

Turn: ($7) J (2 players)
Hero bets $4, BB calls $4.

River: ($15) K (2 players)
Hero checks, BB bets $7.5, Hero raises to ???