Question: What action does the UE take when it receives SIB8 containing a complete warning message and geographical area coordinates?
Option 1: Forward the received warning message, messageIdentifier, serialNumber, dataCodingScheme, and geographical area coordinates to upper layers.
Option 2: Store the received warningMessageSegment and continue reception of SIB8.
Option 3: Discard the warningMessageSegment and associated values of messageIdentifier and serialNumber for SIB8.
Option 4: Start assembling a new warning message for this messageIdentifier and serialNumber pair.
Explanation: According to the specification, when the UE receives SIB8 containing a complete warning message and geographical area coordinates, it forwards the received information to upper layers. This is because all necessary segments have been received, allowing the UE to assemble and forward the complete warning message.