What is a line that connects a customer’s site to a remote CO in another part of the country called?

The correct answer refers to a line that connects a customer's site to a remote central office (CO) in a different region—a direct link used for telecommunications purposes. FX, or Foreign Exchange line, is specifically designed to provide voice communication services between different locations, allowing for efficient transmission of calls as if they were local to the customer's area. This type of line is particularly useful for businesses that need to maintain a presence in different geographical locations without the added cost of multiple local lines.

A tie line typically connects two private branch exchanges (PBXs) within the same company or network, allowing internal communication without going through the public telephone network. A trunk line is a high-capacity communication line that carries multiple signals between two points in a telecommunications system; it is not specific to customer connections. A key system refers to a type of telephone system that allows users to manage multiple lines and calls from a single console, but it does not specifically address the concept of connecting to a remote CO.

Understanding these distinctions helps highlight why FX line is the appropriate term for a dedicated connection to a remote central office.