False. A master server is authoritative for a zone. Parts of the overall domain may have been delegated to subsequent master servers.
A2:
Answer C is correct.
A3:
False. A secondary master name server will use either a forwarders statement if one has been configured in the boot file or will consult a name server listed in the hints file ( db.cache by default).
A4:
True.
A5:
False. The keys used by TSIG authentication on each node need to be the exact same keys. Where the keys are identical on each node, this is known as symmetrical cryptographic authentication.