As other have mentioned, later C= 8bit products were bundled with Geos. A few years back I have a stack of NOS 1541-IIs that all had Geos 1.3 bundled.
Back in the day I remember being very impressed by Geos, but never got it it. Geos was like $70! I could buy 2-3 games with that money! Sigh.. I was a poor kid who had to earn his own $$ for computer stuff. When I did make a little $$, I usually bought games. The exception being saving up money for 8 month to upgrade from C64 to C128.