Final answer:
b. Combatant Commanders exercise Combatant Command (COCOM) authority over assigned forces, which is represented by Operational command authority in the provided choices and is the broadest command authority that cannot be delegated.
Step-by-step explanation:
Combatant Commanders exercise Combatant Command (COCOM) authority over assigned forces. This is the broadest command authority and may not be delegated or transferred. Among the choices provided, such as Tactical command authority, Operational command authority, Administrative command authority, or Strategic command authority, the correct term is not explicitly listed.
However, COCOM, or Combatant Command authority, is implicitly represented by the term 'Operational command authority' (Option B), which refers to a broader scope of command, although COCOM is more specific and accurate in a military context.