The correct answer is B. Cordless telephone system.
A cordless telephone system is a local wireless system that uses radio waves to transmit voice signals between a base station and a handset. The base station is typically connected to a landline telephone, while the handset can be used anywhere within the range of the base station. Cordless telephone systems are often used in homes and offices to provide a convenient way to make and receive calls without having to be tethered to a landline phone.
GSM, UMTS, and EDGE are all examples of cellular networks, which are wireless networks that cover large areas. Cellular networks use a system of base stations to provide coverage, and users can roam between different base stations as they move around. Cellular networks are typically used for mobile phones, but they can also be used for other devices such as laptops and tablets.
In conclusion, the correct answer is B. Cordless telephone system. Cordless telephone systems are local wireless systems that use radio waves to transmit voice signals between a base station and a handset. The base station is typically connected to a landline telephone, while the handset can be used anywhere within the range of the base station. Cordless telephone systems are often used in homes and offices to provide a convenient way to make and receive calls without having to be tethered to a landline phone.