Which of the following uses a remote access server to forward a user's logon password to an authentication server, allowing or denying access to a system?

WPA2-PSK is a Wi-Fi authentication mode where all wireless clients share a single pre-shared key; it does not involve a remote access server forwarding credentials to a separate authentication server.

AES (Advanced Encryption Standard) is a symmetric block cipher algorithm used for data encryption; it is not an authentication protocol and performs no user credential validation or access control functions.

TACACS (Terminal Access Controller Access-Control System) and its successor TACACS+ operate by having a network access server receive a user's login credentials and forward them to a dedicated TACACS authentication server over the network. The authentication server validates the credentials against its database and returns an allow or deny response, enabling centralized access control for multiple network devices without storing credentials locally on each device.

TKIP (Temporal Key Integrity Protocol) is a Wi-Fi data encryption protocol used in WPA networks; it handles encryption of wireless frames and does not perform user authentication or credential forwarding.