What does the Central Office (CO) connect to in telecommunications?

The Central Office (CO) in telecommunications is primarily responsible for connecting all local loops in a given area. The local loop refers to the physical connection between the end user (like a home or business) and the central office, where voice and data signaling can be managed. The central office serves as the primary hub where telephone and broadband services are orchestrated, allowing communication between numerous users and the outside network.

This connection facilitates important functions such as call routing, switching, and service provisioning. Therefore, while the central office may interact with various entities, its foundational role revolves around managing these local loops that directly serve the residential and business environments in its jurisdiction.

The other choices refer to broader or incorrect associations, such as connecting to all private networks in a metropolitan area or all internet service providers in a state, which do not precisely capture the specific function of the central office in relation to local loops. The option regarding telephone handsets within a building is also not accurate, as the CO connects to local loops that may serve multiple buildings and locations, rather than being limited to a single building's handsets.