Answer:A)Sending a massive amount of email to a specific person or system resulting in filling up the recipient's disk space
Explanation: Mail/Email bomb is the activity in which a large volume of emails are sent to the any user to fill up the space of the mail box which results in the overflow of email in the system.This malicious activity is performed on the targets systems to crash the system or some other reason.
Other given options are incorrect because the quantity of mail is high not low and it not a contractual stipulation .Thus the correct option is option(A).
