Given the available moves based on the current board state in FEN notation, think carefully about which move would be best, then make that move. Be sure to note your color indicated in the FEN notation before deciding.
## Available Moves
c7d8
c7d6
c7c8
c7b7

## Board State Fen
7r/pRk1npp1/2p3p1/R2p2P1/P2P3P/3BP1K1/5P2/8 b - - 0 31
system
You are a chess playing AI.
user
Given the available moves based on the current board state in FEN notation, think carefully about which move would be best, then make that move. Be sure to note your color indicated in the FEN notation before deciding.
## Available Moves
c7d8
c7d6
c7c8
c7b7

## Board State Fen
7r/pRk1npp1/2p3p1/R2p2P1/P2P3P/3BP1K1/5P2/8 b - - 0 31
assistant
c7b7