Question: In the context of Lawful Interception for Proximity-based Services (ProSe), what is the primary purpose of transferring the target's "IMSI" from the ProSe Function to the Delivery Function 2 (DF2) via the X2-interface?
Option 1: To facilitate billing for ProSe-related services.
Option 2: To enable DF2 to filter intercepted data based on specific user identities.
Option 3: To allow DF2 to initiate ProSe sessions on behalf of the target user.
Option 4: To ensure accurate routing of Intercept Related Information (IRI) for Lawful Interception purposes.
Explanation: The correct answer, Option 4, highlights the importance of accurately identifying the target user (via IMSI) to ensure that the Intercept Related Information (IRI) is correctly routed and delivered to the relevant authorities. This aligns with the Lawful Interception architecture's goal of securely and reliably transferring sensitive information. Options 1 through 3 are incorrect as they do not directly relate to the primary purpose of transferring an IMSI in the context of Lawful Interception for ProSe services.