I'm making a move at position 2,0 (bottom-left corner) because this will complete a vertical line of three Os in the leftmost column. I already have Os at positions 0,0 (top-left) and 1,0 (middle-left), so placing an O at 2,0 will create a winning line and end the game immediately. This is the optimal move as it allows me to win in this turn rather than blocking or setting up future possibilities.