A chess lesson

A chess game 

White player, 1st opening move, pawn, kings opening, e2 - e4   

Black player,  1st move, knight, g8 - f6 

White player, 2nd move, knight, b1 - c3 

Black player, 2nd move, pawn, e7- e6

White player, 3rd move, bishop, f1 - e2

Black player, 3rd move, bishop, f8 - c5

White player, 4th move, .....?