Question: What is the primary purpose of including `r15:supplementaryUnicastAppService` elements within the `deliveryMethod` element in MBMS (Multimedia Broadcast/Multicast Service) protocols?
Option 1: To provide redundant media components over unicast for users without broadcast coverage.
Option 2: To offer additional, non-redundant media components over unicast, enhancing the user experience when in broadcast coverage.
Option 3: To switch from multicast to unicast transmission for specific media components based on network load.
Option 4: To authenticate user equipment (UE) before granting access to supplementary unicast resources.
Explanation: The inclusion of `r15:supplementaryUnicastAppService` elements is intended to provide an enhanced user experience by offering additional media components over unicast. These components are not redundant with broadcast content and are beneficial even when the user is within broadcast coverage, thereby enriching the application service.