Which of the following is a Reserve Component mentioned in the military service policy?

The Army National Guard is indeed a primary Reserve Component within the military service policy framework. It serves a dual purpose: while it is part of the national military structure, it also has significant roles at the state level, providing assistance during emergencies, natural disasters, and civil disturbances. Members of the Army National Guard can be activated for federal service during times of war or national emergencies, which highlights their unique position as both a state and federal resource.

The other options focus on specific branches or aspects of military service. While the Coast Guard and Naval Reserves play crucial roles, they do not encompass the full definition of a Reserve Component in the same manner as the Army National Guard. Additionally, Air Force Personnel refers more broadly to active duty rather than specifically to reserve components. Thus, the Army National Guard exemplifies the dual-role nature of a Reserve Component effectively, which is why it is the correct choice.