Question: What is the primary security concern addressed by integrity protection and authentication in the "application/mbms-register+xml" MIME type, specifically in the context of MBMS User Service Registration?
Option 1: Preventing unauthorized access to multicast content
Option 2: Protecting user data from eavesdropping during transmission
Option 3: Ensuring the authenticity of the registering entity and preventing modifications to desired registered services
Option 4: Guaranteeing Quality of Service (QoS) for multimedia broadcasts
Explanation: The correct answer highlights the key security considerations. Integrity protection prevents modifications to alter registered services, and authentication ensures the registration request comes from a legitimate source, directly impacting MBMS User Service Registration's security.