Playing in column 3 creates the strongest immediate threat. I already have two O pieces stacked vertically in this column. By placing a third O here, I'll create a vertical three-in-a-row, which forces my opponent to block my potential win on their next turn. This is a strategic advantage as it constrains their options.

Additionally, this move doesn't create any dangerous opportunities for my opponent. I checked for potential diagonal threats that might emerge if I play here, and don't see any immediate risk. 

Column 3 is a strong central position that gives me the most immediate pressure while maintaining good board control.