Which of the following statements is (are) incorrect for firewalls?
A firewall is a system of user identification and authentication that prevents unauthorized users from gaining access to network resources.
Firewall methodologies can be divided into packet filtering, circuit level gateways, and application level gateways. Packet filtering examines packets of data as they pass through the firewall according to rules that have been established.
Application firewall is another name for network firewall. They perform the same function.
IV. No statement above is correct.
a. I only is correct.
b. III only is correct.
c. IV only is correct.
d. II only is correct.