1.e4,c5 2.Nf3,Nc6 3.d4,cxd4 4.Nxd4 and now 4...,e5
Black plays Nf6 only after the white c1 bishop has played to avoid Bg5.
GM Nakamura also takes on d5 with the c-pawn:
GM Carlsen chooses to take on d5 with the e-pawn:
Following that example until move 14:
and another version:
Some take on d5 with the queen:
Some do not have that choice because the knight on d5 is not supported by the c-pawn: