Activity log events - An alert can trigger on every event, or, only when a certain number of events occur. Incorrect Answers: C: Metric values - The alert triggers when the value of a specified metric crosses a threshold you assign in either direction. That is, it triggers both when the condition is first met and then afterwards when that condition is no longer being met. Reference: https://docs.microsoft.com/en-us/azure/azure-sql/database/alerts-insights-configure-portal