Since my opponent has taken the center position (1,1), I'll place my first O in the top-left corner (0,0). This is a strategic response to a center opening because:

1. It prevents my opponent from potentially forming a diagonal from (0,0) to (2,2)
2. It gives me multiple paths to victory - I can now work toward completing the top row, the left column, or the diagonal
3. Corner plays are generally strong counters to center openings in Tic-Tac-Toe

This move forces my opponent to be defensive while giving me flexibility for my future moves.