An administrator wants to configure a FortiGate as a DNS server. The FortiGate must use its DNS database first, and then relay all irresolvable queries to an external DNS server. Which of the…

A non-recursive DNS server would either provide an answer from its local records or refer the client to another server, without performing further lookups on the client's behalf.

The described behavior, where the FortiGate attempts to resolve a query locally and then, if unsuccessful, forwards the query to an external DNS server for full resolution, is the definition of a recursive DNS method.

"Forward to primary and secondary DNS" describes *where* the queries are sent for resolution, not the overall method (recursive vs. non-recursive) of how the FortiGate handles unresolved queries after checking its local database.

"Forward to system DNS" specifies forwarding queries to the DNS servers configured on the FortiGate's system settings, which is a destination, not the specific DNS resolution method.