Best response to the French Defense: Winawer Variation, Positional Variation (C19)

1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Bxc3+ 6. bxc3 Nc6 7. Nf3 Qa5 8. Bd2 Nge7 · White to move

What is the best response to the French Defense: Winawer Variation, Positional Variation (1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Bxc3+ 6. bxc3 Nc6 7. Nf3 Qa5 8. Bd2 Nge7)? White to move. See the top replies ranked by opening theory and real-game results, starting with a4.

The main theoretical reply is a4, reaching the French Defense: Winawer Variation, Positional Variation.