Verifying Attack Manual 1(Quality Chess 2008)-Position 4

Verifying Attack Manual 1(Quality Chess 1st ed 2008)

I have been checking games usually but recently have been neglecting tactical work. Now I'm going through this book which has some exercises in ch9.

Here is the feature game and my notes to solution.

Doettling,Fabian (2542) - Rudolf,Henrik (2327)
King’s Indian Classical 9.b4 [E97]
Bundesliga 0607 Germany (13.8), 18.03.2007

Position 1
The black kingside looks looks but white's potential attacks are far away. What do you recommend for white?
White to Play

19..Rxf4