Question: When a Home Location Register (HLR) updates a Visitor Location Register (VLR) that does not support CAMEL or only supports CAMEL Phase 1, and the Call Forwarding on Not Reachable (CFNRc) registration state is 'Registered' with a non-international forwarded-to number format, how does the HLR modify the CFNRc service state information?
Option 1: The HLR keeps the original service state but converts the forwarded-to number to an international format.
Option 2: The HLR changes the service state to (Provisioned, Not Registered, Not Active, Not Induced) regardless of the previous active or quiescent state.
Option 3: The HLR only updates the VLR with the new registration state if the subscriber's information was previously updated in the HLR.
Option 4: The HLR sends a default forwarded-to number in international format and maintains the original service state.
Explanation: According to specifications, for VLRs without CAMEL support or with only CAMEL Phase 1, if CFNRc is 'Registered' but the forwarded-to number isn't in an international format, the HLR modifies the service state to (Provisioned, Not Registered, Not Active, Not Induced), regardless of its previous state, ensuring VLR compatibility while maintaining accurate HLR records.