Which of the following should you check for and apply regularly so that your server systems are protected from newly discovered virus threats?

A.
A firewall.

B.
Antivirus programs.

C.
Virus software updates.

D.
All of the above.

Explanation:
Virus software updates are released by software manufacturers to protect your server systems from new viruses.
Incorrect
Answers:
A.: If you want to control which server ports are open to the Internet, you should install a firewall solution. A firewall can detect when any intrusion attempts are made as well.
B: Antivirus programs provide protection against viruses that can infect and cause damage to your server systems. Antivirus programs are not applied regularly, virus software updates are.
D: Virus software updates is the correct answer.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 458-459.