Each DNS zone must have a primary server. What are two features of a DNS primary server?
(Choose two.)
A.
They maintain data about each of the top-level zones.
B.
They are the system on which all changes are made to the zone.
C.
They provide update information and synchronize secondary servers when the secondary
servers request information.
D.
They are never authoritative for any domain, except for the loopback address.