Which of the following is a correctly formatted Inmarsat-C address book entry for sending communications to a fax machine on a vessel in the AOR-W?

Correct Answer: Option A — 874336837925

Ship-to-ship Inmarsat-C communications require the Mobile Earth Station (MES) number, which includes the ocean region prefix. The AOR-W region is designated by the prefix 874. Combining this with the vessel's unique 9-digit identification number (336837925) results in 874336837925, the standard format for addressing another vessel's terminal.