UTG bets 14bb after turn check-check

Multi-way River | 4-way: BTN | 100bb effective | Difficulty: Standard

Players in hand: UTG, MP, Hero (BTN), BB

Hero hand

9♥9♣

Board

Q♦7♠2♦J♣A♠

Action so far:
River A♠ on Q♦7♠2♦J♣A♠, pot 20bb
UTG bets 14bb after turn check-check

Pot: 20bb   To call: 14bb

Villain range: UTG delayed river bet on A: AQ, AJ, Ax slowplays, plus rare bluffs

Your move: