Appraisers paid on the basis of a percentage of the value of a property are

Appraisers who are paid based on a percentage of the value of a property are in violation of appraisal ethical standards because it creates a conflict of interest. This practice may incentivize appraisers to deliberately inflate the value of the property in order to earn a higher commission, leading to inaccurate appraisals. Options A, C, and D are incorrect because they do not address the issue of ethical standards and instead focus on other aspects such as negligence or common practice. It is important for appraisers to adhere to ethical standards in order to maintain the integrity and accuracy of their appraisals.