? Passive, as it blocks the d-pawn and thus the queen's bishop. Opening theory suggests Nxe4 or Bc5.
5. d3 b6 6. Bb5xc6
The queen's bishop could've had a nice diagonal through b7, so I took a step to prevent that.
6... dxc6 7. h3
A weak move, only blocking Bg4. Bg5, b3, Nc3 or Re1 would've been natural moves here.
7... c5
ok, but limits the mobility of the king's bishop. With the d-pawn missing it will take a bit of work to get past the pawn at e4, such as Nd7 and then f5. How aobut O-O or Bb7 ?
8. Nb1d2
The idea was to go for the pawn at e5 by doing b3, Bb2, and Nc4. It's easy enough to block, though, with O-O, Re8, and Nd7.
8... b5
?! Prevents Nc4, but the queen's side pawns become more difficult to defend.
9. b3
Preparing to fight for the c4 square, and bringing the bishop to play.
9... O-O 10. Bc1b2 c4
? Loses two pawns for one after bxc4 bxc4 Nxc4, allows the white knight to enter play, isolates the c7 pawn and enables white to attack the e5 pawn.