Which of the following statements would least likely appear in an auditor's engagement letter?

a. Fees for our services are based on our regular per diem rates, plus travel and other out of-pocket expenses.

b. During the course of our audit we may observe opportunities for economy in, or improved controls over, your operations.

c. Our engagement is subject to the risk that material errors, fraud, and defalcations, if they exist, will not be detected.

d. 'After performing our preliminary analytical procedures we will discuss with you the other procedures we consider necessary to complete the engagement.