

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 BB, and your holding is [King of Diamond and Three of Diamond].
Before the flop, UTG raise 2.0 chips, and BB call. Assume that all other players that is not mentioned folded.
The flop comes Nine Of Spade, Seven Of Spade, and Four Of Club, then BB check, and UTG check.
The turn comes Six Of Spade, then BB check, UTG bet 5 chips, and BB call.
The river comes Three Of Club, then BB check, and UTG bet 11 chips.
You currently have One Pair(One Pair, Threes with King, Nine, Seven kickers).

Now it is your turn to make a move.
To remind you, the current pot size is 25.0 chips, and your holding is [King of Diamond and Three of Diamond]. You currently have One Pair.

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: