I need to block my opponent's immediate win threat. X currently has pieces at (1,0) and (1,1), creating a potential win in the middle row if they place at (1,2). By placing my O at this position, I prevent their win.

Additionally, this move gives me potential winning opportunities on the next turn. After placing at (1,2), I'll have my symbol in the rightmost column, which could lead to a column win if I can later place at (0,2). While I'm blocking my opponent's immediate threat, I'm also setting up possible winning paths for myself.