Question: What is the meaning of the Diameter Experimental-Result-Code value "DIAMETER_ERROR_UNKNOWN_MBMS_BEARER_SERVICE" in the context of Interworking between PLMN and PDN?
Option 1: The requested MBMS service is unknown at the BM-SC.
Option 2: The requested MBMS bearer service is not supported by the network.
Option 3: The MBMS service is temporarily unavailable due to maintenance.
Option 4: The BM-SC is unable to process the request due to internal error.
Explanation: This Experimental-Result-Code value indicates that the requested MBMS (Multimedia Broadcast Multicast Service) service is unknown at the Broadcast Multicast Service Center (BM-SC), which is a critical component in the PLMN for providing MBMS services.