Correct Answer: D, ETo achieve Single Log Out (SLO) in the SAML 2.0 Federation with IBM Security Access Manager V9.0 and WebSEAL, it is crucial to configure the mechanisms that handle single signoff requests and ensure proper session tracking for federated sessions. Firstly, configuring the URIs that receive a single signoff request is essential as it defines where the signoff actions are directed. Secondly, adding the appropriate extended attribute to the Federation junction, such as the HTTP-Tag-Value for user_session_id, ensures proper management and tracking of user sessions, which is necessary for achieving SLO.