Explanation/Reference:
Explanation:
The Zone would need to be changed to a AD integrated zone When you use directory-integrated zones, you can use access control list (ACL) editing to secure a dnsZone object container in the directory tree.
This feature provides detailed access to either the zone or a specified resource record in the zone. For example, an ACL for a zone resource record can be restricted so that dynamic updates are allowed only for a specified client computer or a secure group, such as a domain administrators group. This security feature is not available with standard primary zones.
DNS update security is available only for zones that are integrated into Active Directory. After you integrate a zone, you can use the access control list (ACL) editing features that are available in the DNS snap-in to add or to remove users or groups from the ACL for a specific zone or for a resource record.
Standard (not an Active Directory integrated zone) has no Security settings:

You need to firstly change the "Standard Primary Zone" to AD Integrated Zone:

Now there's Security tab:

References:
http://technet.microsoft.com/en-us/library/cc753014.aspx
http://technet.microsoft.com/en-us/library/cc726034.aspx
http://support.microsoft.com/kb/816101