What is the primary function of RADIUS?

The primary function of RADIUS, which stands for Remote Authentication Dial-In User Service, is to provide a centralized method for authenticating and authorizing remote users who connect to a network. This protocol plays a key role in allowing organizations to manage access control for networks that support remote connections, ensuring that only authorized users can access network resources.

RADIUS operates by communicating between a client (like a network access server) and a central server, allowing for authentication requests to be handled securely. When a user attempts to connect to a network, the access server sends the user's credentials to the RADIUS server, which then verifies these credentials against a stored database. If the credentials are valid, the server allows access and can also provide authorization information, such as the specific services or resources the user is permitted to access.

Understanding the other options helps clarify why the correct answer is B. While remote file sharing, remote access and identity verification, and remote authentication in local area networks are all relevant to networking and security, they do not precisely define the comprehensive framework and purpose of RADIUS. The essence of RADIUS revolves specifically around authentication and authorization management for remote users, which aligns perfectly with the full name and functions described in option B.