Final answer:
Do not open the attachment and report the incident to your supervisor or security personnel to handle the situation according to security protocols.
Step-by-step explanation:
If you are working on an unclassified system and receive an email from a coworker containing a classified attachment, you should not open the attachment. The correct action is to report the incident immediately to your supervisor or designated security personnel.
Handling classified information improperly can result in a security breach and may have serious consequences. By reporting the incident, you are ensuring that the issue is handled properly according to your organization's security protocols and maintaining the integrity of the classified information.
When you receive an email from a coworker containing a classified attachment on your unclassified system, you should not open the attachment. Opening the attachment could potentially compromise the security of your system and the classified information. Instead, you should report the incident to your supervisor or security personnel so that appropriate measures can be taken to handle the situation and ensure the security of the classified information.
Therefore correct answer is c) Report the incident to your supervisor or security personnel.