When Inmarsat-B and Inmarsat-C terminals are compared:

Correct Answer: Option C — Inmarsat-B units provide greater communications capabilities, with the trade-offs of greater size, weight, installation expense and initial cost.

Inmarsat-B offers superior communication capabilities, including real-time voice and high-speed data, but requires significant investment in hardware, installation, and maintenance. Inmarsat-C is a more economical, low-bandwidth solution. The trade-off for the advanced services of Inmarsat-B is the increased size, weight, and overall cost of the terminal.