Question: In the context of the Subscriber Identity Module - Mobile Equipment (SIM-ME) interface, what is the mandatory Transmission Protocol that must be supported by both the Mobile Equipment (ME) and the SIM at the Physical and Data link layer?
Option 1: T=1, with optional support for other protocols
Option 2: TCP/IP, as defined in external networking standards
Option 3: T=0, with all other protocols being optional
Option 4: UDP, for efficient data transfer between ME and SIM
Explanation: The correct answer is Option 3 because the support of Transmission Protocol T=0 is explicitly stated as mandatory for both the Mobile Equipment (ME) and the Subscriber Identity Module (SIM) at the Physical and Data link layer, ensuring a baseline compatibility standard across devices.