White to play and mate in 2 moves

Here is a very interesting Chess Puzzle. White to play and mate in 2 moves...

Black has four pawns on the second rank, three of which are only one move away from promotion. But White has nothing to worry, he has an amazing combination up his sleeve. Can you find it? 🙂 It is WHITE TO MOVE AND WIN Study composed by S.M.Birnov (Chess in U.S.S.R, 1935)

White to play and mate in one move... Note: You'll have to make an assumption and the real creative thinking and solution of the puzzle is in the assumption!

Source: ChessBase India

Source: Chessbase India, Youtube

Black to play... Is it time to resign? Or can Black save the game? Can he win?!