Your network consists of a single Active Directory domain. You have a domain controller and a member server that run Windows Server 2008 R2. Both servers are configured as DNS servers. Client computers run either Windows XP Service Pack 3 or Windows 7. You have a standard primary zone on the domain controller. The member server hosts a secondary copy of the zone.You need to ensure that only authenticated users are allowed to update host （A） records in the DNS zone. What should you do first（）
- AOn the member server， add a conditional forwarder.
- BOn the member server， install Active Directory Domain Services.
- CAdd all computer accounts to the DNSUpdateProxy group.
- DConvert the standard primary zone to an Active Directory-integrated zone.