Best response to the Queen's Pawn Game: Symmetrical Variation (D02)

1. d4 d5 2. Nf3 Nf6 · White to move

What is the best response to the Queen's Pawn Game: Symmetrical Variation (1. d4 d5 2. Nf3 Nf6)? White to move. See the top replies ranked by opening theory and real-game results, starting with Nc3.

The main theoretical reply is e3, reaching the Queen's Pawn Game: Colle System.