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 at the 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.