What is the function of a modem?

• A. Increases network throughput
• B. Provides DNS resolution
• C. Communications hardware device that facilitates the transmission of data
• D. Assigns IP addresses

Answer: (C)

The main idea is that a modem serves as the bridge that lets data travel over a communication line by converting signals between digital form (used by your device) and analog form (used by the transmission medium). This modulation and demodulation process enables data to be transmitted over telephone lines, cable, or other networks and then converted back at the other end, making communication possible with an Internet service, other devices, or networks. That’s why the correct description is a communications hardware device that facilitates the transmission of data.

Other options don’t fit because a modem isn’t designed to increase throughput by itself—the actual speed depends on the line and network conditions. It also doesn’t handle DNS resolution or IP address assignment; those tasks are performed by DNS servers and DHCP servers (often by a router or ISP infrastructure), not by the modem alone.