Which channel has been designated for on-scene communications in GMDSS?

Correct Answer: Option B — 16 and 2174.5

VHF Channel 16 is the international distress, safety, and calling frequency, while 2174.5 kHz is the MF DSC distress frequency. Per SOLAS Chapter IV, these are designated for on-scene communications and distress alerting to ensure interoperability between vessels and rescue authorities during emergency operations.