Personally I think “C” is closer to what I think gamers are used to. Look at the PHB for DnD or the Player’s Guide for Deadlands Reloaded. Those generally contain the core of everything you need to know to not only make a character (so your Martial Feats would need to be in it, for example), but also how to use those things.
If you think of CM as more of a GM’s guide then maybe the Beyond Combat sections, or at least those things that are more aimed towards running the game, the setting, etc. could potentially be a separate guide, along with Serious Injuries, Reaction tables, and the like, but I do think at the LEAST it would have be option A, but more likely it’s really Option C unless you have a good way to separate enough “How to run” content from the “Need to run” content. At least that is what I think most people will expect, especially if you use terms like “Player’s Guide” to break it out. It’s just what they would expect to find in most everything else.
