All of the Following Are True About Antivirus Software, Except

Multiple Choice

All of the following are true about antivirus software, except ____.

A) they use known portions of virus code to recognize known viruses
B) they must continually update their files of known viruses
C) they monitor the computer system for unusual activity
D) they permit software with the proper signatures on file to execute
E) they prevent certain commands from executing without further authorization