Question: What is the primary purpose of defining Reference Radio Bearer configurations in conformance testing for User Equipment (UE)?
Option 1: To ensure UE compliance with a specific network's proprietary settings.
Option 2: To guarantee interoperability of UEs across different regions and networks.
Option 3: To provide a comprehensive list of all possible radio bearer configurations.
Option 4: To simplify the testing process by reducing the number of test cases.
Explanation: The correct answer, Option 2, highlights the main objective of Reference Radio Bearer configurations, which is to ensure that UEs can operate seamlessly across various geographical locations and network types. This interoperability is crucial for maintaining consistent user experience and service quality. The other options are incorrect because they either focus on a specific network (Option 1), imply an exhaustive listing of configurations (Option 3), or suggest a simplification of the testing process (Option 4), which are not the primary purposes as per the context provided.