What does the code below do?

What does the code below do?

A.
Any host, from any network, may use this server as its main DNS server.

B.
If the server doesn’t know the answer to a query, it sends a recursive query to 192.168.0.4.

C.
If the server doesn’t know the answer to a query, it sends a query to a root DNS server.

D.
Hosts in the network 10.0.0.0/24 will be able to ask for zone transfers.

E.
If the server doesn’t know the answer to a query, it sends a recursive query to 192.168.0.4 and,
if this fails, it returns a failure.