I'll place my "O" in the top-left corner (0,0). This is a strong opening response when the opponent has taken the center. By taking a corner, I'm setting up multiple potential winning lines (the top row and the left column, plus the diagonal). If my opponent doesn't block one of these threats in their next move, I'll have two ways to win. The corner position also prevents my opponent from immediately forming two-in-a-row, which would force me to play defensively. This move gives me the most strategic flexibility for future turns.