Playing in column 4 is my best option because:
1. It builds on my existing O piece in the bottom row, creating a vertical stack of two O's
2. It creates potential horizontal threats on two different rows
3. It maintains control of the center area of the board, which offers more strategic possibilities
4. It doesn't set up any immediate winning opportunities for my opponent
5. By occupying the center region, I maintain flexibility for future diagonal and horizontal connections