Your company has two domain controllers that are configured as internal DNS servers. All zones  on the DNS servers are Active Directory-integrated zones. The zones allow all dynamic updates.  You discover that the contoso.com zone has multiple entries for the host names of computers  that do not exist.     You need to configure the contoso.com zone to automatically remove expired records.     What should you do（）

• A、Enable only secure updates on the contoso.com zone.
• B、Enable scavenging and configure the refresh interval on the contoso.com zone.
• C、From the Start of Authority tab， decrease the default refresh interval on the contoso.com zone.
• D、From the Start of Authority tab， increase the default expiration interval on the contoso.com zone.