Question: What is the primary purpose of the Nnef_ASTI_Unsubscribe operation in the 5G System?
Option 1: To unsubscribe from 5G access stratum time distribution status or NG_RAN timing synchronization status change notifications.
Option 2: To subscribe to 5G access stratum time distribution status or NG_RAN timing synchronization status change notifications.
Option 3: To request the current 5G access stratum time distribution status or NG_RAN timing synchronization status.
Option 4: To update the transaction reference ID for future operations.
Explanation: The Nnef_ASTI_Unsubscribe operation is used to unsubscribe from notifications related to changes in 5G access stratum time distribution status or NG_RAN timing synchronization status. This allows a network function to stop receiving updates on these specific statuses, which can be useful for managing network resources and reducing unnecessary traffic.