I analyzed the board and noticed that my O’s at (5,2), (4,3) and (3,4) form a promising diagonal potential—if I could eventually play into (2,5) I’d win. However, gravity prevents me from getting (2,5) immediately, and leaving key slots open might allow my opponent to set up their own threats. By playing in the central column 3 (which isn’t full – its next available slot is row3), I both deny my opponent a potential fork (for example, they might try to use column 3 to form their own diagonal) and add flexibility to my own position. This steady, central move helps me maintain my diagonal threat while also opening up opportunities for horizontal connections on row3. For these reasons, I choose column 3 as the best move.