

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 BTN, and your holding is [Nine of Heart and Nine of Diamond].
Before the flop, UTG raise 2.0 chips, and BTN call. Assume that all other players that is not mentioned folded.
The flop comes Four Of Spade, Four Of Heart, and Three Of Heart, then UTG check, and BTN check.
The turn comes Nine Of Spade, then UTG check, and BTN check.
The river comes King Of Club, then UTG check, BTN bet 4 chips, and UTG raise 13 chips.
You currently have Full House(Full House, Nines over Fours).

Now it is your turn to make a move.
To remind you, the current pot size is 22.0 chips, and your holding is [Nine of Heart and Nine of Diamond]. You currently have Full House.

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: