The Inmarsat telephone and TELEX communications channel usage scheme is:

Correct Answer: Option B — One ship per telephone channel and many ships per TELEX channel.

Inmarsat systems utilize Time Division Multiplexing (TDM) for voice channels, dedicating specific bandwidth to a single call. Conversely, TELEX operates via packet-switched protocols, allowing multiple ship stations to share the same frequency channel simultaneously through time-slotted data transmission, optimizing satellite capacity for low-bandwidth text messaging.