Which of the following would indicate an Inmarsat-B terminal?

Correct Answer: Option A — A 9 digit number always starting with 3.

ITU and Inmarsat network formatting rules dictate that Inmarsat-B terminals operate under a 9-digit numbering structure where the leading digit is permanently assigned as 3, separating them from Inmarsat-C (starting with 4) and group/coast assignments.