Your network consists of a single Active Directory domain. All domain controllers run Windows Server 2008 R2 and are configured as DNS servers. A domain controller named DC1 has a standard primary zone for contoso.com. A domain controller named DC2 has a standard secondary zone for contoso.com. You need to ensure that the replication of the contoso.com zone is encrypted. You must not lose any zone data. What should you do（）
- AOn both servers， modify the interface that the DNS server listens on.
- BConvert the primary zone into an Active Directory-integrated zone. Delete the secondary zone.
- CConvert the primary zone into an Active Directory-integrated stub zone. Delete the secondary zone.
- DConfigure the zone transfer settings of the standard primary zone. Modify the Master Servers lists on the secondary