You are designing the configuration of the external DNS server to meet the business and technical requirements.  What should you do？ （）

• A、 Configure a root zone on the external DNS server.
• B、 Configure a stub zone for.com on the external dns server.
• C、 Configure the external DNS server to use the default root hints.
• D、 Configure the External DNS server to use the ISP’S DNS server as a forwarder.