Which of the following reports require a signed certification?

The reason why the answer indicating that all appraisal reports covered in USPAP require a signed certification is correct lies in the fundamental principles established by the Uniform Standards of Professional Appraisal Practice. USPAP mandates that all written and oral appraisal reports must include a signed certification statement to affirm that the appraiser adheres to the ethical obligations and performance standards dictated by the rules.

The certification serves several crucial functions: it attests to the appraiser's independence, objectivity, and compliance with relevant laws and standards, while also confirming that the appraiser has performed the analysis with requisite competence and integrity. By including a signed certification in both written and oral reports, it ensures transparency and accountability, which are critical aspects of maintaining trust in the appraisal process.

While other options may suggest restrictions, such as only written reports or only personal property appraisals, they do not align with USPAP's overarching requirements. This comprehensive application across all appraisal reports underscores the importance of upholding professional standards for the benefit of all stakeholders involved in appraisal activities.