The Urgency signal concerning the safety of a ship, aircraft or person shall be sent only on the authority of:

The correct choice is that the urgency signal concerning the safety of a ship, aircraft, or person shall be sent only on the authority of either the Master of the ship or the person responsible for the mobile station. This is rooted in the principles of maritime communication and safety protocols.

The Master of a ship holds ultimate responsibility for the safety and operation of the vessel, including decisions regarding distress and urgent communication. However, in situations where the Master may not be present or available, the person responsible for the mobile station—such as the first officer or the radio operator—can also initiate such signals. This flexibility ensures that communications can always be made in urgent situations to ensure safety, reflecting the necessity of prompt action in emergencies where lives could be at risk.

In this context, the involvement of either individual allows for a rapid response in critical scenarios. It is essential that these signals are sent accurately and promptly to coordinate necessary assistance and navigation resources effectively. This cooperative authority structure is crucial for maintaining safety at sea and in aviation, underlining the importance of clear lines of communication in emergency situations.