Best response to the Grünfeld Defense: Exchange Variation, Spassky Variation (D89)

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Bc4 c5 8. Ne2 Nc6 9. Be3 O-O 10. O-O Bg4 11. f3 Na5 12. Bd3 cxd4 13. cxd4 Be6 · White to move

What is the best response to the Grünfeld Defense: Exchange Variation, Spassky Variation (1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Bc4 c5 8. Ne2 Nc6 9. Be3 O-O 10. O-O Bg4 11. f3 Na5 12. Bd3 cxd4 13. cxd4 Be6)? White to move. See the top replies ranked by opening theory and real-game results, starting with d5.

The main theoretical reply is d5, reaching the Grünfeld Defense: Exchange Variation, Sokolsky Variation.