According to the ethical standards of the profession, which of the following acts is generally prohibited? A) Issuing a modified report explaining a failure to follow a governmental regulatory agency's standards when conducting an attest service for a client. B) Revealing confidential client information during a quality review of a professional practice by a team from the state CPA society. C) Accepting a contingent fee for representing a client in an examination of the client's federal tax return by an IRS agent. D) Retaining client records after an engagement is terminated prior to completion and the client has demanded its return. Give a detailed explanation for the correct answer.