Question: What is a capability of the 3GPP System when a user requests to access a service, in relation to User Identity authentication with a User Identifier?
Option 1: The 3GPP System can only authenticate users if the service has no specified authentication policies.
Option 2: The 3GPP System supports authentication of the User Identity towards the service if the level of confidence complies with the service's specified policies.
Option 3: The 3GPP System always denies access to a service if the user's association with a User Identifier is not established.
Option 4: The 3GPP System can bypass User Identity authentication for services accessed via non-3GPP networks.
Explanation: This option correctly reflects the capability of the 3GPP System to support User Identity authentication with a User Identifier towards a service, but only if the level of confidence in the correct association of the User Identity with the User Identifier meets the specified policies of the service.