The SOA is the specific record type found in every zone and contains information that identifies the sever primarily responsible for the zone as well as some operational properties for the zone.
Explanation:
The Start of Authority Records (SOA) has the following information they are
Serial Number: This number is used to find when zonal information should be replicated.
Responsible person: The Email address of a person is responsible for managing the zone.
Refresh Interval: It specifies how often a secondary DNS server tries to renew its zone information.
Retry Interval: It specifies the amount of time a secondary server waits before retrying the zone information has failed.
Expires After: IT specifies the amount of time before a secondary server considers its zone data if it can't contact with the primary server.
Minimum TTL: It specifies the default TTL value for a zone data when a TTL is not supplied.
Answer: a. RADIUS
Explanation:
RADIUS as developed with the idea of allowing its users or clients to be able to authenticate to a dial-in access server. So basically it is a client server protocol and he client here is the firebox and the server is the RADIUS server.
The authentication mechanism start by user who sends a message to the RADIUS server. Then the RADIUS server upon receiving the message accept or denies it. It accepts if the client is configured to the server.
A large amount of additional information can be sent by the RADIUS server in its Access-Accept messages with users so we can say that RADIUS is uitable for what are called "high-volume service control applications" such as dial-in access to a corporate network.