I'm choosing column 4 because it builds upon my existing O piece at the bottom of this column. This starts developing a vertical line of my pieces, which could lead to a vertical win if I can continue building upward. Additionally, this position works with my O pieces in column 3 to potentially create diagonal winning opportunities in future moves. There are no immediate threats from my opponent that I need to block, so this offensive move gives me the best chance to develop winning positions.