A repeater is a network device that retransmits a received signal with more power and to an extended geographical or topological network boundary than what would be capable with the original signal. A repeater is implemented in computer networks to expand the coverage area of the network, repropagate a weak or broken signal, and or service remote nodes. Repeaters amplify the received/input signal to a higher frequency domain so that it is reusable, scalable, and available. Repeaters were introduced in wired data communication networks due to the limitation of a signal in propagating over a longer distance and now are a common installation in wireless networks for expanding cell size. Repeaters are also known as signal boosters. Hence based on the functions of repeaters statements B and D are correct.