Question: What action should a Mobile Equipment (ME) take when receiving a DL NAS TRANSPORT message with a secured packet containing an SMS-Deliver for SIM data download, and the integrity check is successful?
Option 1: Display an alert to the user indicating a new message.
Option 2: Pass the message transparently to the UICC using the ENVELOPE (SMS-PP DOWNLOAD) command without user notification.
Option 3: Store the message locally for later processing and notify the user of pending messages.
Option 4: Reject the message due to security protocol constraints.
Explanation: According to specified behavior, when an ME receives a valid DL NAS TRANSPORT message with an SMS-Deliver for SIM data download, it must forward this message directly to the UICC using the defined ENVELOPE command without alerting or displaying the content to the user, ensuring secure and transparent processing.