I'm choosing column 3 because it allows me to create a horizontal sequence of three Os in columns 3, 4, and 5. This sets up a potential winning opportunity if I can later place a piece in column 2 or 6. Additionally, by playing in column 3, I'm blocking a potential vertical build-up by my opponent in this central column. This move gives me the best combination of offense (creating my own threats) and defense (preventing opponent's opportunities).