In a geostationary satellite communication system, a message signal is transmitted from an earth station via an uplink to a satellite, amplified in a transponder onboard the satellite, and then transmitted via a downlink to another earth station. The most popular frequency band for satellite communication is

• A. 16 MHz for the uplink and 14 MHz for the downlink
• B. 4 GHz for the uplink and 6 GHz for the downlink
• C. 6 GHz for the uplink and 4 GHz for the downlink
• D. 10 GHz for the downlink and 8 GHz for the uplink