The correct operation is D because email attachments are a common carrier for malware, phishing payloads, ransomware, Trojans, and malicious scripts. In enterprise security practice, a user should not trust an attachment only because the message looks work-related or appears to come from a company mailbox . Attackers can spoof sender information, disguise malicious content, or compromise legitimate accounts. Therefore, simply checking the content or sender is not enough to ensure safety.
A safer process is to verify the sender and the email details carefully , such as the address, subject, wording, unexpected urgency, and whether the attachment type matches the business context. After that, the attachment should be scanned with antivirus or endpoint security software before opening or saving it. This helps detect known malicious files and reduces the chance of infecting the host or internal network.
Option A is unsafe because work relevance alone does not prove the file is harmless. B is clearly wrong because attachments can directly affect information security. C is also unsafe because internal-looking mail can still be malicious. Therefore, D is the correct answer.