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
b5a4
b5c4
b5b4
e5f4
a6a5
d6b8
d6c7
d6f8
d6e7
e6f7
e6f6
e6e7
e6d7
g6g5

## Board State Fen
8/8/p1pbk1pB/1pp1p2p/P1P1PP1P/1P3KP1/8/8 b - - 4 42
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
b5a4
b5c4
b5b4
e5f4
a6a5
d6b8
d6c7
d6f8
d6e7
e6f7
e6f6
e6e7
e6d7
g6g5

## Board State Fen
8/8/p1pbk1pB/1pp1p2p/P1P1PP1P/1P3KP1/8/8 b - - 4 42
assistant
b5a4