The correct answer is B. Certain INMARSAT systems can automatically transmit when called, exposing individuals to potentially harmful radiation. INMARSAT-C terminals, in particular, focus the transmitter's signal into a fine beam, which can pose a radiation risk if not handled properly. In contrast, INMARSAT-A and B antennas are omnidirectional and generally considered safer. The INMARSAT unit's ray dome does not filter out UV rays, so answer A is incorrect. Answer C is also incorrect, as the INMARSAT-C antenna's focused beam is the source of potential radiation exposure, not the antenna itself.