Which of the following conditions can render INMARSAT-B communications impossible?

The conditions that can render INMARSAT-B communications impossible include several factors that affect signal quality and availability. Each of the factors listed in the choices contributes to potential disruptions in communication.

The first condition involves the blockage of a satellite signal by tall buildings. INMARSAT-B relies on direct line-of-sight to the satellite for effective communication. When the signal from the satellite encounters physical obstructions, such as tall buildings, it can be partially or completely blocked, leading to interrupted service.

The second condition pertains to traveling beyond the effective radius of the satellite. INMARSAT-B satellites cover specific geographical areas, known as footprints. If a user moves outside of this coverage area, the satellite communication will be impossible because there is no satellite signal accessible to the device.

The third factor is strong rain causing attenuation. Satellite signals can be weakened by heavy precipitation due to absorption and scattering of the radio waves. This phenomenon can lead to reduced signal strength and, in severe cases, the complete loss of communication when conditions are particularly adverse.

Since each of these conditions alone can impede the ability to communicate via INMARSAT-B, and they collectively reinforce the point that environmental and physical factors are critical in maintaining effective satellite communication, the inclusion of "All