Explanation: The Global Maritime Distress and Safety System (GMDSS) is an international framework established by the International Maritime Organization (IMO) to enhance safety at sea and facilitate search and rescue operations. It is specifically mandated for ships that fall under the International Convention for the Safety of Life at Sea (SOLAS). This convention applies to most commercial vessels engaged in international voyages, and the requirement for GMDSS equipment specifically kicks in for SOLAS Convention ships of 300 gross tonnage or more. This ensures that larger vessels operating globally are equipped with reliable distress and safety communication systems. Option A is too broad, as not all vessels capable of international voyages are subject to SOLAS regulations (e.g., small pleasure craft). Option C describes a *purpose* of GMDSS (global coverage) but not the *requirement* for its carriage, which is regulatory. Option D is incorrect because GMDSS is generally not required for vessels *less than* 300 gross tons under SOLAS.