Which of the Following Source of Evidence Would Be the Most

Multiple Choice

Which of the following source of evidence would be the most reliable:

A) a written confirmation sent by a bank directly to the auditor.
B) a written confirmation sent by a debtor to the client.
C) a written document produced electronically by a client with good internal controls.
D) a written document in the form of a fax sent by a debtor to the client indicating acceptance of a special offer.