Question: What is the primary purpose of the `Notify_RealtimeUAVStatus` API operation in the context of Uncrewed Aerial System (UAS) support at the application layer?
Option 1: To request and retrieve real-time UAV status information from a UAS application specific server.
Option 2: To notify the UAS application specific server of changes in real-time UAV status information.
Option 3: To establish a persistent connection for future UAV status updates between the UAS and its application server.
Option 4: To authenticate UAVs before granting access to the UAS network.
Explanation: The `Notify_RealtimeUAVStatus` operation is used to inform or update (notify) the UAS application specific server about changes or the current state of the UAV's status in real-time, rather than requesting information. This aligns with the operation's described purpose as a 'Notification of the realtime UAV status information' towards the UAS application specific server.