Best response to the Indian Defense: Spielmann-Indian (A46)

1. d4 Nf6 2. Nf3 c5 · White to move

What is the best response to the Indian Defense: Spielmann-Indian (1. d4 Nf6 2. Nf3 c5)? 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 Benoni Defense: Benoni-Indian Defense, Kingside Move Order.