Question: Upon receiving a short message TPDU from a Mobile Station (MS), what action does the Serving GPRS Support Node (SGSN) take if it detects incorrect parameters in the RP-DA parameter inspection?
Option 1: The SGSN transfers the short message TPDU to the SMS-IWMSC for further processing.
Option 2: The SGSN relays a success report to the MS, indicating successful transmission.
Option 3: The SGSN temporarily stores the message for later reattempt.
Option 4: The SGSN returns appropriate error information to the MS in a failure report.
Explanation: When the SGSN identifies incorrect parameters during the RP-DA inspection, its responsibility is to notify the MS of the error. This is achieved by sending back a failure report containing the relevant error details, ensuring the MS is informed of the transmission issue and can potentially retry or correct the mistake.