Question: What is the primary purpose of the security function in EPS that involves authentication of the UE by the network?
Option 1: To provide user data and signalling confidentiality.
Option 2: To authenticate the network by the UE.
Option 3: To provision origin authentication of signalling and user data.
Option 4: To guard against unauthorised EPS service usage.
Explanation: The security function in EPS that involves authentication of the UE by the network is primarily used to prevent unauthorized access to the EPS services. This is achieved by verifying the identity of the UE and ensuring that it has the necessary permissions to access the requested services.