I noticed that in the bottom row (row5), columns 1, 2, and 3 are occupied by X. If X were to drop a piece in column 0 on its next move, it would create a horizontal line of 4 (columns 0, 1, 2, 3) and win the game. To block this immediate threat, I will drop my piece in column 0, ensuring that X cannot win next turn. Therefore, the best move is column 0.