∴(x-2)^5=y-2x,y=f(x)=(x-2)^5+2x，

G (x) = f (x+2)-4 = x 5+2x, odd function, increasing function,

f(a 1)+f(a2)+...+f(a9)=36，

∴g(a 1-2)+g(a2-2)+……+g(a9-2)=0，

Sequence {an} is an arithmetic series with tolerance not equal to 0.

∴g(a5-2)=0,a5-2=0,a5=2，

∴ A 1+A2+...+A9 = 9A5 = 18。 Choose C.