1.Nf3 f6 2.Nd4 Nh6 3.h3 b5

White can play:

4.Nf5 Nxf5 5.d4 (5.e4 g6) e6 (or 5...g6; 5...d5) 6.d5 (6.e4 g6 7.d5 Bh6),

4.e3 g6 5.Bd3 f5 6.Qf3.