Which frequencies and modes are allocated for distress alerting in GMDSS?

Correct Answer: Option D — All of the above

GMDSS utilizes a multi-layered distress alerting system. Channel 70 (VHF DSC), 406 MHz EPIRBs, and Inmarsat satellite systems are all integral components mandated by SOLAS Chapter IV to ensure reliable, global distress alerting capabilities regardless of a vessel's geographic location or proximity to coastal stations.