【单选题】View the Exhibit to examine the output of the DBA_OUTSTANDING_ALERTS view. After 30 minutes, you executed the following command: SQL> SELECT reason,metric_value FROM dba_outstanding_alerts; REASON ...
A.
An Automatic Workload Repository snapshot has been taken recently.
B.
The non-threshold-based alerts are transferred to DBA_ALERT_HISTORY.
C.
The threshold alerts conditions are cleared and the alerts are transferred to DBA_ALERT_HISTORY.
D.
The threshold alerts related to database metrics are permanently stored in DBA_ALERT_HISTORY but not the threshold alerts related to instance metrics.