

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 [Ace of Spade and Nine 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 3 chips, BB raise 10 chips, and UTG call.
The river comes King Of Spade, then BB bet 12 chips, and UTG raise 44 chips.
You currently have Flush(Flush, Ace-high).

Now it is your turn to make a move.
To remind you, the current pot size is 80.0 chips, and your holding is [Ace of Spade and Nine of Diamond]. You currently have Flush.

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: