Question: In a Mobile Radio Interface Layer 3 scenario, what triggers the return of the 'specialServiceCode' error?
Option 1: Rejection of a User-to-User Signalling service request by the network
Option 2: Diversion to a special service code being requested
Option 3: Failure to establish a call due to insufficient network resources
Option 4: Incorrect formatting of the deflectionToServedSubscriber request
Explanation: The 'specialServiceCode' error is specifically returned when there's an issue related to diverting a call or service to a special service code, as indicated by the request for such diversion. This highlights the importance of proper handling of special service codes within telecom networks to avoid unnecessary errors and ensure seamless user experience.