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
b4a3
b4a5
b4c3
b4c5
b4a4
b4b3
b4c4
b4b6
b4b5
d6d5
e6c4
e6d5
e6c8
e6d7
e6h3
e6g4
e6f5
f6e4
f6g4
f6d5
f6d7
f6h5
g6g5
b7b5
b7b6
g7f8
g7h6
g7h8
h7h5
h7h6
a8a1
a8a2
a8a3
a8a4
a8a5
a8a6
a8a7
a8d8
a8c8
a8b8
e8b8
e8c8
e8d8
e8f8
g8h8
g8f8

## Board State Fen
r3r1k1/1p2ppbp/3pbnp1/8/1qP1P3/1PNB3P/2QB1PP1/1R2R1K1 b - - 4 18
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
b4a3
b4a5
b4c3
b4c5
b4a4
b4b3
b4c4
b4b6
b4b5
d6d5
e6c4
e6d5
e6c8
e6d7
e6h3
e6g4
e6f5
f6e4
f6g4
f6d5
f6d7
f6h5
g6g5
b7b5
b7b6
g7f8
g7h6
g7h8
h7h5
h7h6
a8a1
a8a2
a8a3
a8a4
a8a5
a8a6
a8a7
a8d8
a8c8
a8b8
e8b8
e8c8
e8d8
e8f8
g8h8
g8f8

## Board State Fen
r3r1k1/1p2ppbp/3pbnp1/8/1qP1P3/1PNB3P/2QB1PP1/1R2R1K1 b - - 4 18
assistant
b4b6