Respond with a "Refused" error message (default)
Using this option, you specifically inform the client (or other DNS server) that you will not provide any data for the requested name.
Respond as if the zone was not configured on this server
The server will respond as if the zone wasn't on this server.
If the IP address sending the DNS request is not offered recursion (see Recursion section), the request will be treated as lame, and responded to (or not) according to the settings in the Lame Requests section.
Respond with synthesized DNS records
Using this option, you can redirect anyone requesting suspended names for example to a "this web-site is temporarily suspended" web-page.