In the actual game, I played 9.Nb1 but it seems black gets a nice lead after 9...Qa5 10.a3 c5.
That brings us to white's last option 9.Nce2 (diagram). White denies black of an immediate target and increases the pressure on black's king side as the knight can now quickly move to g3 or f4 to support the advance of the g and h pawns.
Black has a large range of replies, but none seems to provide an advantage.
a/ 9...Qa5 10.Kb1 (diagram)
...a1/ 10...c5 11.h4 (=)
...a2/ 10...Rd8 11.Nc1 (+=)
...a3/ 10...Be6 11.Nc1 (+=)
...a4/ 10...Bd7 11.Nc1 (+=)
...a4/ 10...Bd7 11.Nc1 (+=)
...a5/ 10...Bb7 11.h4 (+=)
...a6/ 10...Ba6 11.h4 (=)
...a7/ 10...Na6 11.g5 (+=)
...a8/ 10...Ba6 11.h4 (=)
...a9/ 10...Nbd7 11.g5 (=)
...a0/ 10...Nfd7 11.h4 (+=)
...aA/ 10...Ne8 11.h4 (+=)
...aB/ 10...d5 11.e5 (+=)
...aC/ 10...h5 11.gxh5 (+=)
...aD/ 10...a6 11.Nc1 (+=)
b/ 9...Qb6 10.Nf4 (+=)
c/ 9...Qc7 10.Nf4 (+=)
d/ 9...a5 10.h4 (diagram)
...d1/ 10...a4 11.h5 ( more prudent than 11.Qxb4 )
......d1a/ 11...b3 12.cxb3 axb3 13.a3 (+=)
......d1b/ 11...Qa5 12.Nf4 (+=)
...d2/ 10...h5 11.Nf4 hxg4 12.h5 (+=)
...d3/ 10...Qb6 11.h5 (+=)
...d4/ 10...Ba6 11.Bh6 (+=)
e/ 9...Ba6 10.h4 ( again more prudent than 11.Qxb4 )
...e1/ 10...Qa5 11.h5 !! Qxa2 12.Qxb4 (=)
...e2/ 10...h5 11.Ng3 (+=)
...e3/ 10...Nd7 11.h5 (+=)
f/ 9...d5 10.e5 (+=)
g/ 9...c5 10.dxc5 Qa5 11.g5
...g1/ 11...Ne8 12.Kb1 (=)
...g2/ 11...Nfd7 12.cxd6 Qxa2 13.Qxb4 (+=)
...g3/ 11...Nh5 12.Kb1 (=)
h/ 9...h5 10.gxh5 Nxh5 11.Ng3 ( safer than 11.Qxb4 )
...h1/ 11...Nf6 12.h4 (+=)
...h2/ 11...Qa5 12.Kb1 (+=)
...h3/ 11...Nxg3 12.hxg3 (+)
......d1a/ 11...b3 12.cxb3 axb3 13.a3 (+=)
......d1b/ 11...Qa5 12.Nf4 (+=)
...d2/ 10...h5 11.Nf4 hxg4 12.h5 (+=)
...d3/ 10...Qb6 11.h5 (+=)
...d4/ 10...Ba6 11.Bh6 (+=)
e/ 9...Ba6 10.h4 ( again more prudent than 11.Qxb4 )
...e1/ 10...Qa5 11.h5 !! Qxa2 12.Qxb4 (=)
...e2/ 10...h5 11.Ng3 (+=)
...e3/ 10...Nd7 11.h5 (+=)
f/ 9...d5 10.e5 (+=)
g/ 9...c5 10.dxc5 Qa5 11.g5
...g1/ 11...Ne8 12.Kb1 (=)
...g2/ 11...Nfd7 12.cxd6 Qxa2 13.Qxb4 (+=)
...g3/ 11...Nh5 12.Kb1 (=)
h/ 9...h5 10.gxh5 Nxh5 11.Ng3 ( safer than 11.Qxb4 )
...h1/ 11...Nf6 12.h4 (+=)
...h2/ 11...Qa5 12.Kb1 (+=)
...h3/ 11...Nxg3 12.hxg3 (+)
So we see that white gets great attacking lines after 9.Nce2. Black is able to equalize in some lines - but hey, that's life !