Question: In an MBMS setup, what is a prerequisite for the availability of the Media Presentation Description (MPD) metadata fragment, as indicated by the presence of the `mediaPresentationDescription` element?
Option 1: At least one of the delivery methods shall be a streaming delivery method.
Option 2: At least one of the delivery methods shall be a download delivery method.
Option 3: The MBMS User Service Description fragment must include a URI for a live broadcast.
Option 4: The DASH client must have previously accessed a similar media presentation.
Explanation: According to the specifications, for the Media Presentation Description (MPD) metadata fragment to be available, at least one of the delivery methods must be a download delivery method. This ensures that the DASH client can access the MPD via a download, crucial for constructing the associated media presentation for the end user.