What type of firewall architecture employs two network cards and a single screening router?

A.
A dual-homed host firewall

B.
An application-level proxy server

C.
A screened-subnet firewall

D.
A screened-host firewall

Explanation:
Like a dual-homed host, a screened-host firewall uses two network cards to connect to the trusted
and untrusted networks, but adds a screening router between the host and the untrusted network. *
dual-homed host has two NICs but not necessarily a screening router. * screened-subnet firewall
uses two NICs also, but has two screening routers with the host Exhibit:

acting as a proxy server on its own network segment. One screening router controls traffic local to
the network while the second monitors and controls incoming and outgoing Internet traffic, *
application-level proxy, is unrelated to this question. Source: Hacker Proof by Lars Klander (Jamsa
Press, 1997).