I'm choosing column 1 for several strategic reasons. First, it positions my piece adjacent to my existing O in column 2, giving me the start of a potential horizontal connection. Second, it prevents my opponent from potentially building downward from that position later. Third, by playing here rather than column 5 (which would block their immediate horizontal expansion), I'm avoiding creating a setup where my opponent could place a piece in column 5 and then have multiple winning threats. This move balances offense (starting my own line) with defense (controlling the left side of the board).