French Defense Traps #2

This move order can look like black is winning a pawn:

1.e4 e6 2.d4 d5 3.e5 c5 4.Nf3 Nc6 5.Bd3

But taking the pawn with Knight, results in that white can easy win back it's pawn by continue playing:

5...Nxd4 6.Nxd4 cxd4 7.Bb5+ Bd7 8.Bxd7+ Qxd7 9.Qxd4

Taking with the c5 pawn is considered mainline, and white continues with 6. 0-0