Final answer:
Cellular telephones utilize microwaves, a type of high-frequency electromagnetic wave used in various communication technologies due to their efficient production and long-distance propagation capabilities.
Step-by-step explanation:
Cellular telephones utilize C. microwaves for communication. Microwaves are a type of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter, corresponding to frequencies between 300 MHz (1 GHz) and 300 GHz. This frequency range is suitable for wireless communication due to its ability to carry information effectively over long distances without a direct line of sight.
Cell phones operate in the microwave range of the electromagnetic spectrum, typically in the gigahertz (GHz) range. The most common bands for cellular communication include the 800 MHz, 900 MHz, 1.8 GHz, 2.1 GHz, and 2.4 GHz bands. These microwaves are utilized in a process called radiofrequency (RF) communication, where voice and data signals are modulated onto carrier waves for transmission and reception by mobile devices.
Contrary to some misconceptions, cellular phones do not use x-rX-rays which have much shorter wavelengths and higher frequencies. X-rays are ionizing radiation and are not suitable for communication purposes due to their potential harm to living tissues. In summary, cellular telephones primarily rely on microwaves (option C) for wireless communication, enabling the seamless transmission of voice and data over extensive cellular networks.