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.