Raoul Has Received a File Attachment from a Known Individual

Multiple Choice

Raoul has received a file attachment from a known individual. He has no reason to expect files from this individual. Which of the following is an effective security strategy for Raoul to take?

A) Open the file attachment and use anti-virus software to scan it.
B) Before opening the attachment, use anti-virus software to scan the system's hard disk.
C) Make back-up copies of important files so that it is possible to recover them in case of an incident.
D) Before opening the attachment, call or send a text or instant message to the individual to verify that he or she meant to send it.