Which system is least likely to be affected by atmospheric disturbances?

Correct Answer: Option B — Inmarsat

Inmarsat utilizes satellite-based communication, which operates at microwave frequencies unaffected by the ionospheric and atmospheric disturbances that degrade terrestrial MF/HF radio waves. By bypassing the ionosphere, Inmarsat provides consistent, reliable global coverage, making it the most robust system against the environmental interference typically encountered in maritime radio propagation.