Question: In a scenario where a VLR only supports Phase 1 call handling, how are calls forwarded on no reply handled regarding subaddress transmission from the HLR to the VLR?
Option 1: The HLR passes the subaddress to the VLR for all call forwarding scenarios.
Option 2: The HLR never passes the subaddress to the VLR for any call handling phase.
Option 3: Calls are forwarded without the subaddress since the HLR does not pass it to a Phase 1-only VLR.
Option 4: The decision to forward with or without subaddress depends on the subscriber's service state information.
Explanation: This is correct because, in the context of a VLR that only supports Phase 1 call handling, when a call is forwarded on no reply, the HLR does not pass the subaddress to the VLR, resulting in calls being forwarded without the subaddress. This highlights the technical impact of limited phase support on call forwarding behaviors in telecom networks.