Name a key document that governs Army National Guard operations.

The Army National Guard Regulation (AR 600-1) is a key document that defines the policies, procedures, and guidelines that govern the operations of the Army National Guard. It provides essential information regarding personnel, training, and readiness standards specific to the Army National Guard. This regulation outlines the roles and responsibilities of both leaders and soldiers, ensuring that everyone understands their duties in order to maintain operational effectiveness and readiness.

Choosing this regulation as the correct answer emphasizes the importance of following specific guidelines tailored to the Army National Guard, reflecting its unique mission within the overall structure of the military. Other documents, while significant to the broader military or governance context, do not provide the same level of operational detail or focus as AR 600-1 does for National Guard personnel. For example, the National Defense Act outlines the general framework of national defense but does not address day-to-day operations or regulations specific to the Army National Guard.