You are the network administrator for your company. All network servers run Windows Server 2003 Service Pack 2 （SP2）. You deploy a DNS server named DNS1 that runs Windows Server 2003 SP2.  You need to configure DNS1 to use your ISP’s DNS servers to resolve all Internet queries. Internet name resolution should fail if the ISP’s DNS servers are unavailable.  What should you configure on DNS1 server？（）

• A、Add the ISP’s DNS servers to the root hints. Delete the other root hints.
• B、Add the ISP’s DNS servers to the root hints. Delete the %systemroot%/system32/dns/root.dns file.
• C、Configure the ISP’s DNS servers as forwarders. Deselect the Enable netmask ordering option.
• D、Configure the ISP’s DNS server as a forwarder. Select the Do not use recursion for this domain option.