Which two rules must appraisers understand and comply with according to Advisory Opinion 39?

The correct choice highlights the essential rules that appraisers must be familiar with to ensure their work aligns with the standards set forth in the Uniform Standards of Professional Appraisal Practice (USPAP). The Ethics Rule establishes fundamental ethical principles that guide appraisers, ensuring integrity, honesty, and impartiality in their work. Meanwhile, the Competency Rule mandates that appraisers possess the necessary knowledge and skills to perform their appraisal services competently.

Advisory Opinion 39 specifically emphasizes these two rules because they are crucial for maintaining the credibility of appraisals and protecting the interests of clients and the public. By adhering to these rules, appraisers not only uphold professional standards but also contribute to the overall trustworthiness of the appraisal profession. Understanding these rules is essential for successful practice and compliance within the industry.