I'm choosing column 4 because it blocks a potential future vertical threat by X in that column while also starting to build my own horizontal potential threat with the O's at the bottom. This move places my piece at the third row from the bottom, which gives me better board control and creates more winning opportunities for future turns. Additionally, none of the available moves give me an immediate win or require an immediate block of an opponent's winning move, so building my own positive position is the best strategy.