Answer:
B. fax cover sheets
Step-by-step explanation:
A fax cover sheet is a page that includes the sender's contact information, the intended recipient of the fax, the information of this recipient, and any other information that the sender considers relevant. These sheets are generally faxed to the recipient before he receives the actual fax message. Although these sheets are usually optional, they can be useful when conveying important information to the recepient of a fax.