Which of the following is not a reason why the auditor requests that the client provide a letter of representation?

Which of the following is not a reason why the auditor requests that the client provide a letter of representation?

a. Professional auditing standards require the auditor to obtain a letter of representation.
b. It impresses upon management its responsibility for the accuracy of the information in the financial statements.
c. It provides written documentation of the oral responses already received to inquiries of management.
d. It provides written documentation, which is a higher quality of evidence than management’s oral responses to inquiries.