Which frequency/mode is authorized for use internationally for Maritime Safety Information transmissions?

Correct Answer: Option B — 4209.5 kHz using FEC mode

The frequency 4209.5 kHz is internationally designated for NAVTEX-type broadcasts using FEC mode. This frequency is utilized globally to provide MSI to vessels beyond the range of terrestrial NAVTEX stations, ensuring consistent access to safety information through the HF NBDP system as mandated by IMO GMDSS standards.