Final answer:
A Multiplexer allows a computer to maximize the utilization of a group of frequencies by combining multiple signals into a single channel.
Step-by-step explanation:
The telecommunication system that allows a computer to maximize the utilization of a group of frequencies is a Multiplexer. A multiplexer works by combining multiple signals on a single channel, which increases the efficiency of the communication channel. It allows several signals, such as phone lines or network connections, to be transmitted together without interference, using different frequencies. This is crucial in systems where bandwidth is limited, as it enables the transmission of signals on one system without deteriorating the quality of the transmission.