What is the BEST method for mitigating against network denial of service (DoS) attacks?

A.
Ensure all servers are up-to-date on OS patches

B.
Employ packet filtering to drop suspect packets

C.
Implement network address translation to make internal addresses nonroutable

D.
Implement load balancing for Internet facing devices

Explanation:

Packet filtering techniques are the only ones which reduce network congestion caused by a
network denial of service (DoS) attack. Patching servers, in general, will not affect network traffic.
Implementing network address translation and load balancing would not be as effective in
mitigating most network DoS attacks.