31.White to move

In the position above it looks like an equal position for both side .The question is

a)From your point of view what is the best continuation for white to play?

Thanks to Name and Mr..... for solving problem 30 by 1.Nb6 Nxb6 2.Rc7 Qe8 3.Qe6+ Kg7 4.Bb2+ Kh6 5.Nf7+ Kh5 6.Qh3++..There are lot of continuation of move occur but the key move is 1.Nb6 and 2.Rc7 that eliminate all counter of move from Black.