Explanation: 406 MHz EPIRBs (Emergency Position-Indicating Radio Beacons) are digital distress alerting devices. When activated, they transmit coded bursts of data on the 406 MHz frequency. This data contains a unique hexadecimal identification number that is pre-programmed into the beacon and registered with a national authority (like NOAA in the United States). This registration links the beacon's ID to vital information about the vessel and its owner, allowing Search and Rescue (SAR) authorities to quickly identify the party in distress and access emergency contact details. Option B is incorrect because 406 MHz EPIRBs are designed for digital data transmission, not voice communication with rescue centers. Option C is incorrect as the primary coded information transmitted is the unique ID and, if GPS-equipped, the position, not the method of activation (manual or automatic). Option D is incorrect because EPIRB IDs are pre-programmed and registered, not programmed by the operator immediately prior to activation, and it confuses an EPIRB with a SART (Search and Rescue Transponder), which is a different device altogether.