BTN bets 10bb (half pot)

Heads-up River | BB vs BTN | 100bb effective | Difficulty: Easy

Hero hand

A♣K♣

Board

K♥7♦4♠9♣2♥

Action so far:
Hero check-calls flop and turn
River 2♥
BTN bets 10bb (half pot)

Pot: 20bb   To call: 10bb

Villain range: KQ,KJ,KT,QQ,JJ,bluffs (busted gutters and FDs)

Your move: