Which of the following is an effective method for controlling downloading of files via FTP? Choose the BEST
answer.

A.
An application-layer gateway, or proxy firewall, but not stateful inspection firewalls

B.
An application-layer gateway, or proxy firewall

C.
A circuit-level gateway

D.
A first-generation packet-filtering firewall

Explanation:
Application-layer gateways, or proxy firewalls, are an effective method for controlling downloading of files via
FTP. Because FTP is an OSI application-layer protocol, the most effective firewall needs to be capable of
inspecting through the application layer.