A ship operating in sea area A-3 must have the following provisions for maintenance:

Correct Answer: Option D — Any two of the above

Sea Area A3, defined as the coverage area of Inmarsat satellites, requires a higher level of reliability. Vessels must implement any two of the three recognized maintenance options—duplication, at-sea, or shore-based—to ensure that critical distress and safety communications remain operational even if one primary system fails during a voyage.