Question: In the context of Lawful Interception (LI) for 3G security, what is the primary purpose of sending a LawfulIntercept message with a keep-Alive parameter from the Mediation Function (MF) to the Law Enforcement Monitoring Facility (LEMF)?
Option 1: To initiate a new LI session for intercepting user data.
Option 2: To transfer intercepted user data in bulk.
Option 3: To indicate to the LEMF that the LI connection is still active after a configurable period of inactivity.
Option 4: To request configuration updates from the LEMF for LI parameters.
Explanation: The keep-Alive parameter's role is to maintain the LI connection. If no LawfulIntercept message has been sent for a configurable amount of time, a LawfulIntercept message with a keep-Alive parameter is sent to signal to the LEMF that the LI connection remains active, preventing unnecessary termination due to inactivity.