What is the maximum distance at which the controlling agency must forward changes in the MOA activity schedule to all FSSs?

The correct answer reflects the established regulation regarding the distance at which changes in the Military Operations Area (MOA) activity schedule must be communicated to all Flight Service Stations (FSSs). In this case, the maximum distance is set at 100 miles. This requirement ensures that the FSSs are adequately informed of any changes within that radius, allowing them to provide timely and accurate information to pilots and aviation personnel operating in the vicinity of the MOA.

This regulation is essential for maintaining safety and efficiency in air traffic by ensuring that pilots are aware of active airspace operations that could affect their flight paths. By adhering to this distance requirement, the controlling agency can effectively manage flight safety and keep all relevant parties informed of any alterations in scheduled military activities.

In contrast, the other distance options do not comply with the established regulations, as they either do not provide sufficient coverage for timely updates or extend beyond the necessary parameters set for optimal communication. This guideline fosters a collaborative environment between military operations and civilian air traffic, crucial for seamless airspace management.