Question: When a Mobile Equipment (ME) receives a "network currently unable to process command" result, what is the mandatory action for providing additional information, specifically regarding the first byte of the Cause Information element?
Option 1: The first byte should be set to 'FF' to indicate an unknown cause.
Option 2: The ME shall generate a random value for the first byte to ensure uniqueness.
Option 3: The first byte must match the last byte of the previous successful command.
Option 4: The first byte shall be the cause value returned by the network, with Bit 8 set to '1'.
Explanation: This is correct because when the ME encounters a "network currently unable to process command" scenario, it must provide additional information in a standardized manner. The first byte of the Cause Information element should reflect the cause value provided by the network, with Bit 8 set to '1' to indicate this specific condition, ensuring interoperability and consistent error handling across different network implementations.