Barbara explained to her friend Sue that she has a virus checker installed on her computer which scans each email for viruses. Sue recommended that Barbara periodically scan her entire computer system for email viruses. Barbara said that she won't scan her computer for email viruses periodically because it takes so much time and slows down her computer. Furthermore, Barbara said that there's no point to rescan her files because one or two scans is enough. Using the concepts you have learned in this class, how should you advise Barbara?
There is no need to rescan for email viruses because they are no longer a threat.
There is no need to rescan for email viruses. She should instead just not open attachments.
She should rescan periodically to prevent zero-day viruses from infecting her system.
There is no need to scan for email viruses because her virus checker already scans the email when it is received.