Answer:
The scenario you described, in which a user receives an email warning of a dangerous computer virus and is instructed to delete critical system files, is an example of a hoax. A hoax is a false or deceptive message that is designed to trick or deceive the recipient.
Step-by-step explanation:
In this case, the email warning of a dangerous virus is likely a hoax, as deleting critical system files can cause serious problems with the operating system and can render the computer inoperable. It is important to be cautious when receiving emails that contain warning messages or instructions to delete files, and to verify the information before taking any action.
Other examples of hoaxes include false alerts about security vulnerabilities or threats, false reports of celebrity deaths, and false offers or promotions. It is important to be aware of these types of hoaxes and to verify the information before taking any action or sharing it with others.