GMDSS: Element 7

1. A Ch-12 in the 16 MHz band.
2. B Ch-1216 in the MF band.
3. C Ch-16 in the 12 MHz band.
4. D This would indicate the 16th channel in the 12 MHz band, but Ch-1216 does not yet exist as there are currently only 15 possible channels.

Tip: press A-D to answer