A wireless network uses a RADIUS server that is connected to an authenticator, which in turn connects to a supplicant. Which of the following represents the authentication architecture in use?

Open systems authentication is a simple Wi-Fi authentication method where no credentials are required from the client, and it does not utilize a RADIUS server or the three-party architecture described.

A captive portal is a web-based authentication method that redirects users to a specific page before granting network access, describing a user interface layer rather than the fundamental underlying authentication architecture involving a RADIUS server and an authenticator.

RADIUS federation refers to the practice of trusting RADIUS servers from other organizations to authenticate users, which is an inter-organizational trust concept, not the internal network authentication architecture described.

802.1x is an IEEE standard for port-based network access control that specifies a three-component architecture: a supplicant (client), an authenticator (access point or switch), and an authentication server (typically a RADIUS server). This precisely matches the description of a wireless network using a RADIUS server connected to an authenticator, which connects to a supplicant for authentication.