Answer:
A. Sending a massive amount of email to a specific person or system that can cause that user's server to stop functioning.
Explanation:
Mail bomb is a cyber attack involving sending huge volumes of email to a specific address so as to overwhelm the mailbox. As a result the email server may also get choked and the electronic communication mechanism can be compromised. This is one of the actions that form part of destructive hacking where an attacker tries to disrupt productive activities of an individual or enterprise.
