Answer:
The correct answer is letter "B": Verify the sources and contents of the faxes in telephone calls to the senders.
Step-by-step explanation:
After a confirmation is sent to a debtor, it is a good practice to contact by phone the department of charge of receiving the document in the debtor's end to make sure they have received the confirmation. It is important also to verify the content of the confirmation so that the debtor agrees in the correctness of the document, which immediately gives them the responsibility of paying the amount bill.