Question: What action does the MSC take if errors are indicated by the VLR during the retrieval of information for an MT-SMS, specifically after sending 'sendInfoFor-MT-SMS'?
Option 1: Transfer the short message to the MS with error appended.
Option 2: Relay the error information to the SMS-GMSC in a delivery report.
Option 3: Return the appropriate error information to the SMS-GMSC in a failure report (negative outcome of 'forwardShortMessage').
Option 4: Store the TPDU in a queue indefinitely until the MS is available.
Explanation: When the MSC receives an indication of errors from the VLR during the process of sending 'sendInfoFor-MT-SMS' for an MT-SMS, it cannot proceed with transferring the message to the MS. Instead, it must inform the SMS-GMSC about the failure. This is done by returning the appropriate error information in a failure report, which corresponds to a negative outcome of the 'forwardShortMessage' operation. This ensures that the sender (or the system) is notified of the delivery failure, aligning with standard practices for handling errors in message delivery within telecom networks.