A violation of the profession's ethical standards most likely would have occurred when a CPA:
a. Issued an unqualified opinion on the 1992 financial statements when fees for the 1991 audit were unpaid.
b. Recommended a controller's position description with candidate specifications to an audit client.
c. Purchased a CPA firm's practice of monthly write-ups for a percentage of fees to be received over a three-year period.
d. Made arrangements with a financial institution to collect notes issued by a client in payment of fees due for the current year's audit