Which two statements are true about alerts（） A: Clearing an alert sends the alert to the alert history. B: Response actions cannot be specified with server-generated alerts. C: The nonthreshold alerts appear in the DBA_OUTSTANDING_ALERTS view. D: Server-generated alerts notify the problems that cannot be resolved automatically and requireadministrators to be notified.

Which two statements are true about alerts（） A: AClearing an alert sends the alert to the alert history. B: BResponse actions cannot be specified with server-generated alerts. C: CThe nonthreshold alerts appear in the DBA_OUTSTANDING_ALERTS view. D: DServer-generated alerts notify the problems that cannot be resolved automatically and requireadministrators to be notified.