After the termination of monitoring 121.5 MHz distress signals, which entities will continue monitoring these signals?

The choice stating that overflying aircraft or nearby air traffic control facilities will continue to monitor 121.5 MHz distress signals is correct because these entities maintain a listening watch on emergency frequencies, even after the primary monitoring by ground stations has been officially terminated.

121.5 MHz is the designated frequency for emergency and distress calls in aviation, and it is critical for the safety of aircraft operating in flight. Overflying aircraft are equipped with transceivers that can receive transmissions on this frequency, allowing them to assist in distress situations if needed. Similarly, air traffic control facilities in proximity to a distress signal are dedicated to maintaining safety in the airspace and will continue to monitor emergency frequencies to facilitate timely responses to any potential emergencies.

In contrast, ground control only is not the correct choice because ground facilities may cease monitoring once their designated duty period ends. Military aircraft, while they have capabilities to monitor distress signals, do not constitute the primary entities continuing monitoring post-termination. Therefore, they are not solely responsible for ongoing monitoring of 121.5 MHz. Commercial airlines are similarly not exclusively responsible for this monitoring, as any aircraft in the vicinity or capable of receiving the signal may contribute to this safety net.