Question: What is the primary purpose of the f5 and f5* key generating functions in a telecom network's security protocol, as defined by industry standards?
Option 1: To compute Message Authentication Codes (MACs) for secure messaging
Option 2: To derive temporary session keys for encrypting voice calls
Option 3: To generate random numbers for subscriber authentication challenges
Option 4: To compute Authentication Keys (AK) for normal operation and re-synchronization, respectively
Explanation: In telecom security protocols, f5 and f5* are key generating functions. Their primary purpose is reflected in the correct answer: f5 computes the Authentication Key (AK) normally, while f5* does so for re-synchronization, maintaining secure connections under varying conditions.