Losing the Exchange

Matthew Wilber (Buffalo Grove) - Eric Rosen (Niles North)

White to play

So bishops and knights are worth 3 pawns or so and rooks are worth 5 pawns or so.  So if you lose a rook for a knight plus a pawn, you've lost one point, right?

Losing a rook for a knight or bishop is called "losing the Exchange".   In the above position, Black is down the Exchange for a pawn.  (We capitalize "the Exchange" to distinguish it from plain old exchanges of pieces, I suppose.)

If you've lost the Exchange for a pawn, don't fret!  Your extra pawn can hope to become a queen, but your opponent's rook is trapped in its body!  Knights are more fun than rooks!  And you now have one more piece than your opponent!

Check out the above position.  Black's knights are getting frisky, the center pawns look scary, and the White rooks don't have enough room to come out and play.  What's White's best move?

P.S.  If you haven't figured out the answer already, enjoy the full game.