Question: During a combined tracking area updating procedure in an Evolved Packet System (EPS), what may the Mobility Management Entity (MME) initiate?
Option 1: EMM common procedures, such as authentication and security mode control.
Option 2: Only handover or inter-system handover to S1 mode.
Option 3: Tracking area updating procedure without involving EMM common procedures.
Option 4: Detach from the network due to security concerns.
Explanation: The MME may initiate EMM common procedures, such as authentication and security mode control, during a combined tracking area updating procedure in an EPS. This is necessary for maintaining security and ensuring proper authentication of the User Equipment (UE) in the network.