Your network contains an Active Directory domain named contoso.com.     You remove several computers from the network.     You need to ensure that the host （A） records for the removed computers are automatically  deleted from the contoso.com DNS zone.     What should you do（）

• A、Configure dynamic updates.
• B、Configure aging and scavenging.
• C、Create a scheduled task that runs the Dnscmd /ClearCache command.
• D、Create a scheduled task that runs the Dnscmd /ZoneReload contoso.com command.