On vacation at the beach, you bring a radio to the beach. the radio can pick up several different radio stations. which is the best explanation for this?

a) sound waves can travel from through the air from the station to your radio.

b) radio stations broadcast from different locations using their own transmitters.

c) sound of different pitches are used to transmit information from each radio station. these sound waves can travel over land.

d) waves are used to transmit the radio signal through the air. these waves are encoded at different frequencies for different stations.