Question: In CN-initiated selective deactivation of a UP connection for an existing PDU Session involving I-SMF, which entities replace the SMF and UPF in the procedure?
Option 1: The I-SMF and I-UPF.
Option 2: The AMF and SGW.
Option 3: The MME and PGW.
Option 4: The HSS and PCRF.
Explanation: In the context of CN-initiated selective deactivation for a PDU Session involving I-SMF, the SMF and UPF roles are specifically taken over by the I-SMF (Interface-Service Management Function) and I-UPF (Interface-User Plane Function), respectively. This replacement is crucial for managing the session and user plane functions in scenarios where I-SMF is involved.