What kind of network covers large geographical areas and often relies on phone companies?

The correct answer focuses on Wide Area Networks (WANs), which are designed to cover large geographical areas, such as cities, states, or even countries. WANs connect multiple Local Area Networks (LANs) and allow for data communication over distances that cannot be achieved by LANs. They often utilize the existing telecommunications infrastructure, such as that provided by phone companies, to facilitate this long-distance communication. This makes WANs especially valuable for businesses and organizations with operations spread across different locations.

While the other types of networks serve specific functions, they do not fit the description provided in the question. For example, Campus Area Networks (CANs) are typically limited to university campuses or business complexes, localizing services within a more confined area. Peer-to-Peer Networks (P2P) enable direct sharing between devices without a dedicated server but do not inherently support large geographical coverage. Local Area Networks (LANs) are restricted to smaller areas, such as a single building or a group of nearby buildings, and are not designed for extensive geographic reach. Thus, WANs are uniquely positioned to incorporate vast areas and commercial infrastructures like those of telecommunications companies.