Question: In the EFSMSR (Short message status reports) EF, what does the first byte of each record primarily represent?
Option 1: The SMS status report's protocol discriminator
Option 2: A timestamp for when the status report was received
Option 3: A link to the corresponding short message in EFSMS (e.g., a record identifier)
Option 4: An indicator of the SMS bearer service used
Explanation: The first byte of each record in EFSMSR serves as a reference or identifier that connects the status report to its corresponding short message, ensuring correct association for managing and updating the status of sent or received short messages.