These commands are established by combatant commanders when authorized by the Secretary of Defense through the Chairman of the Joint Chiefs of Staff to conduct operations on a continuing basis in accordance with the criteria set forth for unified commands. They may be established on a geographic area basis such as U. S. Forces Japan or on a functional basis such as Special Operations Command, Pacific. a. Subordinate Unified Commands
b. Combatant Command
c. Unified Command Plan
d. None of above

b. Combatant Command

Explanation:

The Combatant commands are commands which are primarily authorized by the Secretary of Defense with approval from the President. They are then executed by the Combatant Commanders (CCDR's), who receive information from the higher authorities through the Chairman of the Joint Chiefs of Staff. The combatant commanders head the combatant commands and are usually four-star Generals. The combatant commands have a broad and continuing purpose.

They ensure synergy for the command and control of the United States military forces. They are formed on the basis of geography or function. The United States Defense Department has eleven (11) combatant commands which serve either a geographic or functional purpose.