In which one of the following situations would a CPA be in violation of the AICPA Code of Professional Conduct in determining a fee? A) A fee based on whether the CPA's report on the client's financial statements results in the approval of a bank loan. B) A fee based on an estimate of the number of hours needed to complete the engagement by auditors of various levels of experience. C) A fee based on the nature of the service rendered and the CPA's particular expertise instead of the actual time spent on the engagement. D) A fee based on the fee charged by the prior auditor. Please give a detail explanation to the correct answer.