Which of the following best describes the data flow in a cable modem?

The data flow in a cable modem is accurately described by the process of modulation and demodulation of signals. A cable modem takes digital signals from a computer or local network and converts (modulates) these signals into analog signals that can be sent over the coaxial cable to the internet service provider (ISP). This process allows the digital data to be transmitted over the cable television infrastructure. Conversely, when data is received from the ISP, the modem demodulates the incoming analog signals back into digital form for use by the local network.

This dual-role function is essential for the communication between the internet and local devices, as it allows for bidirectional data flow. Therefore, choosing this answer illustrates a fundamental understanding of the cable modem's purpose in converting between digital data used by devices and the analog signals used for transmission over the cable network.