Question: What triggers a User Equipment (UE) to enter the 5GMM-REGISTERED state?
Option 1: When the UE performs a periodic registration update.
Option 2: When the UE receives a registration request from the network.
Option 3: When the UE successfully completes an initial registration procedure.
Option 4: When the UE is powered on and establishes a connection with the network.
Explanation: The correct answer is Option 3 because, according to the provided text, the state 5GMM-REGISTERED is entered at the UE when the initial registration procedure is performed by the UE. This indicates that the successful completion of an initial registration procedure triggers the UE to enter this state.