Question: What is the requirement for an operator regarding support for CAMEL or IN services for their IMS (IP Multimedia Subsystem) Core Network (CN) subsystem subscribers?
Option 1: Mandatory support for both CAMEL and IN services.
Option 2: No requirement to support either CAMEL or IN services, but can offer access if desired.
Option 3: Conditional support based on the number of IMS CN subsystem subscribers.
Option 4: Required support for at least one of CAMEL or IN services.
Explanation: This option correctly reflects the flexibility given to operators. The specification emphasizes that there is no requirement for an operator to support CAMEL or IN services for their IMS CN subsystem subscribers, implying they can choose to offer these services at their discretion.