Best response to the Queen's Gambit Declined: Modern Variation (D50)

1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 · Black to move

What is the best response to the Queen's Gambit Declined: Modern Variation (1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5)? Black to move. See the top replies ranked by opening theory and real-game results, starting with Nbd7.

The main theoretical reply is Nbd7, reaching the Queen's Gambit Declined: Modern Variation, Knight Defense.