An organization finds unauthorized software has been installed on a number of workstations. The software was found to contain a Trojan which had been uploading data to an unknown external party.
Which of the following would have BEST prevented the installation of the unauthorized software?
A . Implementing application blacklisting
B . Implementing an intrusion detection system (IDS)
C . Banning executable file downloads at the Internet firewall
D . Removing local administrator rights
Answer: D