Central offices are primarily connected to which of the following?

Central offices serve as critical nodes in telecommunications networks, primarily handling the routing of calls and data. The correct answer identifies that central offices are primarily connected to Class 4 offices.

Class 4 offices, also known as tandem offices, function as intermediaries in the network, connecting multiple Class 5 offices, which directly serve individual subscribers. The relationship between central offices and Class 4 offices is integral to the handling of trunk lines and managing the flow of calls between different regions.

In this context, the role of Class 4 offices is to process and route communications between various Class 5 subscribers, illustrating their importance in ensuring effective connectivity across broader network structures. By serving this function, Class 4 offices facilitate communication not just within localized areas but also across more extensive network deployments, ensuring a seamless exchange of information.

While Class 3 offices, individual subscribers, and international offices play roles in telecommunications, they do not directly represent the primary connection point for central offices in the same way that Class 4 offices do. Class 3 offices are typically involved in processing data traffic for larger network segments but do not serve as the main hub for central office connectivity. Individual subscribers are end-users and not another type of office, while international offices pertain to