Which statement is true regarding National Guard and state active duty forces?

The statement that National Guard and state active duty forces are under multiple headquarters supporting federal civil authorities is accurate because these forces often operate under both state and federal command structures, depending on the situation. When activated for federal missions, such as during natural disasters or national emergencies, the National Guard can be placed under federal command while simultaneously maintaining their state identity and responsibilities. This dual-status ability allows for enhanced coordination and integration of resources to provide effective support to civil authorities.

Moreover, during domestic operations, the National Guard works closely with various local, state, and federal agencies. This collaboration is crucial for emergency management and disaster relief efforts, ensuring that all responding forces can seamlessly communicate and execute their missions, thus reinforcing the idea that these forces operate under multiple headquarters to effectively support civil authorities at different levels.