Concept:Radio transmission is the sending and receiving of information using radio waves, which are a form of electromagnetic radiation.Explanation:The equipment shown in Figure 1 communicates without the use of physical cables.It does not depend on infrared light or an Ethernet connection for its main function.Radio waves allow the device to transmit and receive signals over a distance.This is the same principle used in broadcasting, wireless communication and remote-control devices.Therefore, the equipment in Figure 1 is used for radio transmission.Answer:D. radio transmission
