Explanation: INMARSAT satellites utilize a geostationary orbit. This specific type of orbit allows the satellite to appear stationary from a fixed point on Earth, which is crucial for maintaining continuous communication links without requiring constant antenna tracking. For a satellite to be geostationary, its orbital period must precisely match the Earth's rotational period (approximately 23 hours, 56 minutes). This synchronous orbit is achieved at a specific altitude of approximately 22,236 miles (35,786 kilometers) above the Earth's surface at the equator. Option B, 22,177 miles, is the closest and most commonly cited value for this critical geostationary altitude. The other altitudes listed would result in different orbital periods, meaning the satellite would drift relative to the ground, making continuous communication challenging or impossible without complex tracking systems.