Which of the following types of firewalls would BEST protect a network from an internet attack?

A.
Screened subnet firewall

B.
Application filtering gateway

C.
Packet filtering router

D.
Circuit-level gateway

Explanation:

A screened subnet firewall would provide the best protection. The screening router can be a
commercial router or a node with routing capabilities and the ability to allow or avoid traffic
between nets or nodes based on addresses, ports, protocols, interfaces, etc. Application-level
gateways are mediators between two entities that want to communicate, also known as proxy
gateways. The application level (proxy) works at the application level, not just at a package level.
The screening controls atthe package level, addresses and ports, but does not see the contents of
the package. A packet filtering router examines the header of every packet or data traveling
between the internet and the corporate network.