

You are a specialist in playing 6-handed No Limit Texas Holdem. The following will be a game scenario and you need to make the optimal decision.

Here is a game summary:

The small blind is 0.5 chips and the big blind is 1 chips. Everyone started with 100 chips.
The player positions involved in this game are UTG, HJ, CO, BTN, SB, BB.
In this hand, your position is CO, and your holding is [King of Spade and Jack of Spade].
Before the flop, CO raise 2.3 chips, and BTN call. Assume that all other players that is not mentioned folded.
The flop comes Jack Of Club, Jack Of Heart, and Four Of Spade, then CO check, and BTN check.
The turn comes Four Of Diamond, then CO check, BTN bet 8 chips, and CO call.
The river comes Three Of Club, then CO bet 11 chips, and BTN raise 40 chips.


Now it is your turn to make a move.
To remind you, the current pot size is 73.0 chips, and your holding is [King of Spade and Jack of Spade].

Decide on an action based on the strength of your hand on this board, your position, and actions before you. Do not explain your answer.
Your optimal action is: