Question: In a GSM network, what type of information do the Elementary Files (EFs) within the dedicated file DFSoLSA primarily contain, as specified in the SIM-ME interface standards?
Option 1: Details for international roaming configurations
Option 2: User's preferred language settings for SMS
Option 3: Encryption keys for secure data transmission
Option 4: Information about the user's subscribed local service areas
Explanation: The correct answer, Option 4, aligns with the specification that the EFs in DFSoLSA contain information about the users' subscribed local service areas. This is crucial for network operations to manage and provide services based on a user's geographical subscription coverage. Understanding the contents of these files is essential for effective service provisioning and management in telecom networks, particularly in relation to location-based services and billing.