What can be implemented to provide the highest level of protection from external attack?

A.
Layering perimeter network protection by configuring the firewall as a screened host in a
screened subnet behind the bastion host

B.
Configuring the firewall as a screened host behind a router

C.
Configuring the firewall as the protecting bastion host

D.
Configuring two load-sharing firewalls facilitating VPN access from external hosts to internal
hosts

Explanation:
Layering perimeter network protection by configuring the firewall as a screened host
in a screened subnet behind the bastion host provides a higher level of protection from external
attack than all other answers.