Your company has a single Active Directory Domain Services （AD DS） domain named PassGuide.com that uses Active Directory-integrated DNS. You deploy the Key Management Service （KMS） on a Windows 7 computer. You need to ensure that Windows 7 client computers can locate the KMS host and perform activation.   Which two actions should you perform？（）

• A、Deploy a Windows Server 2008 KMS host.
• B、Grant the KMS server the Full Control permission on the _vlmcs._tcp.PassGuide.com DNS record.
• C、Grant the KMS server the Full Control permission on the _msdcs._tcp.PassGuide.com DNS zone.
• D、Create and deploy a GPO firewall rule to allow RPC traffic through TCP port 1688 on the client computers.