Queen's Gambit Declined - Janowski variation
1. d4 d5 2. c4 e6 3. Nc3 a6
White plays the queen's pawn to d4. Black moves the queen's pawn to d5. White plays the c-pawn to c4.
Black advances the king's pawn to e6. White develops the knight to c3. Black moves the a-pawn to a6.