Question: In SMS as per 3GPP specifications, what is the minimum level of nested grouping that an implementation must support for grouped elements in a message?
Option 1: No nesting is allowed for grouped elements
Option 2: At least 2 levels of nested group
Option 3: Exactly 1 level of nested group
Option 4: Up to 5 levels of nested group (implementation dependent)
Explanation: This is crucial for ensuring compatibility and proper parsing of SMS messages with complex grouping structures. Supporting at least 2 levels of nesting allows for more sophisticated message layouts while maintaining a baseline for all implementations, thus ensuring interoperability across different devices and networks.