This line aims to challenge Black’s bishop on b4 and prepare for potential pawn breaks on the queenside. In response, Black can play:
\[1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2\]
\[4...d5 5.a3 Bxc3+ 6.Qxc3\]