Final answer:
The first action you should take is to update your antivirus software. Forwarding the email or deleting the files immediately without updating your antivirus software is not recommended. So the correct answer is option D.
Step-by-step explanation:
The first action you should take in response to this email is to update your antivirus software. Updating your antivirus software will ensure that it has the latest virus definitions and can detect and protect against the new threat described in the email.
Deleting the files immediately without updating your antivirus software is not recommended, as there's a possibility that the threat may have already infected your system.
Forwarding the email to friends and family is also not recommended, as it could potentially spread the threat to others. Instead, you should report the email as spam to your email provider so they can take appropriate action against the sender.