Explanation/Reference:
Explanation:
Name protection requires secure update to work. Without name protection DNS names may be hijacked.
You can use the following procedures to allow only secure dynamic updates for a zone. Secure dynamic update is supported only for Active Directoryintegrated zones. If the zone type is configured differently, you must change the zone type and directory-integrate the zone before securing it for Domain Name System (DNS) dynamic updates.
1. (B) Convert primary DNS server to Active Directory integrated primary
2. (D) Enable secure dynamic updates

Reference: DHCP: Secure DNS updates should be configured if Name Protection is enabled on any IPv4 scope
http://technet.microsoft.com/en-us/library/ee941152(v=ws.10).aspx