Question: In a USIM application, what is the specific content composition of the EFWLRPLMN (I-WLAN Last Registered PLMN) file when service n°84 is 'available'?
Option 1: Mobile Network Code (MNC) followed by Location Area Code (LAC)
Option 2: International Mobile Subscriber Identity (IMSI) in full
Option 3: Access Point Name (APN) for WLAN interworking
Option 4: Mobile Country Code (MCC) followed by the Mobile Network Code (MNC)
Explanation: The correct composition of the EFWLRPLMN file, as per telecom standards for USIM applications, specifically requires identifying the last registered PLMN for I-WLAN services. This is achieved by combining the Mobile Country Code (MCC), which identifies the country, with the Mobile Network Code (MNC), which identifies the network within that country. This combination uniquely identifies a PLMN, ensuring proper registration and service provisioning in WLAN interworking scenarios.