Final answer:
The pilot of the aircraft in distress is responsible for broadcasting a distress cancellation to inform appropriate authorities that the emergency situation has been resolved.
Step-by-step explanation:
When it comes to broadcasting a distress cancellation, the responsibility lies with A. The pilot of the aircraft in distress. It is the pilot's duty to inform the relevant authorities that the distress situation has been resolved. Upon resolving the emergency, the pilot should communicate with the nearest air traffic control unit to cancel the distress status. This ensures that the rescue coordination centers and any other involved parties are updated, and it helps prevent unnecessary search and rescue operations. It is neither the duty of the aircraft's passengers, the first aircraft on the scene, nor the air traffic control unit to broadcast the distress cancellation; these entities may assist, but final responsibility lies with the pilot.