Which of the following terms BEST describes a system which allows a user to log in and access multiple related servers and applications?

Remote Desktop Protocol (RDP) is a proprietary Microsoft protocol used to remotely access and control a single desktop or server interface, not a system for managing authentication across multiple applications.

Federated Identity Management (FIM) is a broader framework that enables identity and authentication data to be shared across different organizational trust domains or enterprises, whereas the question describes a single-login-to-multiple-resources scenario which is more precisely SSO.

Single sign-on (SSO) is specifically designed to allow a user to authenticate once and then gain access to multiple related servers and applications without re-entering credentials. It works by issuing an authentication token after the initial login, which is then accepted by other systems within the same trust domain. This directly matches the scenario described of logging in once to access multiple related resources.

Multi-factor authentication (MFA) is a security mechanism that requires users to provide two or more verification factors to authenticate, which strengthens login security but does not itself enable access to multiple systems with a single login.