Question: In which scenario is the "UE status" Information Element (IE) included in the registration procedure?
Option 1: When a UE in single-registration mode changes from S1 mode to N1 mode.
Option 2: When a UE in dual-registration mode and EMM state EMM-DEREGISTERED performs initial registration.
Option 3: When a UE in single-registration mode performs the registration procedure due to intra-system change within S1 mode.
Option 4: When a UE in dual-registration mode and EMM state EMM-REGISTERED performs periodic registration update.
Explanation: The "UE status" IE is included when a UE in single-registration mode changes from S1 mode to N1 mode, as this indicates an inter-system change that requires the UE to perform the registration procedure. This ensures that the network is aware of the UE's new status and can manage its connectivity accordingly.