I'm choosing column 4 because it allows me to place an O directly above my existing O in row 3, creating a vertical pair. This builds toward a potential vertical win and capitalizes on my existing position. While columns 2 and 5 also allow me to create vertical pairs, column 4 builds on an already advanced position (one space higher on the board), giving me a head start toward a potential vertical win. There are no immediate threats I need to block, so building my strongest offensive line is the best strategy.