Question: What is the purpose of including the Additional Update Result IE in the NAS protocol?
Option 1: To provide the UE with information about the result of a detach procedure.
Option 2: To request the UE to perform a combined attach procedure for EPS services and non-EPS services.
Option 3: To inform the UE about the outcome of an attach procedure, including whether it was successful for EPS services and "SMS only".
Option 4: To initiate a tracking area update procedure.
Explanation: The Additional Update Result IE is used to provide the UE with additional information about the result of an attach procedure. This includes whether the procedure was successful for EPS services and non-EPS services, or for EPS services and "SMS only". This information helps the UE to determine its current state and take appropriate actions.