Which type of network utilizes PSTN lines for communication?

The correct answer is the type of network that utilizes PSTN (Public Switched Telephone Network) lines for communication is classified as a WAN (Wide Area Network). PSTN lines are designed primarily for voice communication and have traditionally been used for telephone services. WANs cover large geographic areas, often spanning cities, countries, or even continents, and they utilize various communication methods, including PSTN lines, to connect different networks or devices over vast distances.

In the context of network types, LAN (Local Area Network) typically refers to networks that operate within a limited area, such as a home or office building, and they typically use Ethernet or Wi-Fi for connectivity rather than relying on PSTN lines. MAN (Metropolitan Area Network) serves a larger area than a LAN but is still confined to a city or a large campus, and it may utilize fiber optics, wireless, or other communication technologies but does not primarily depend on PSTN lines. The "None of the above" option indicates that there is no relevant network type present in the other choices, making it invalid in this scenario. Therefore, recognizing that WANs use multiple forms of communication, including PSTN lines, clarifies why this option is the most accurate.