check call, bet call, or check fold

[chimpanzepoopdic]

Loose passive 4/8 game
2 middle players call, Hero raises from the CO with AJ offsuit, the button calls and the BB calls.
5 players, the flop is K64 rainbow.
First three players check, Hero bets, button calls and the BB calls.
The turn is 7 and everyone checks.
The river is a Jack and BB checks.
Hero check calls, bet calls, or check folds?