Final answer:
An appraiser's signature is mandated only on the final page of the appraisal report to verify their involvement and agreement with the statements in the certification.
Step-by-step explanation:
The statement that is true regarding an appraiser's signature obligations is option b) An appraiser's signature is required only on the final page of the appraisal report.
According to the Uniform Standards of Professional Appraisal Practice (USPAP), the appraiser must sign the certification part of the report, which is commonly on the last page. The signature verifies the appraiser's direct involvement in the development of the appraisal and agrees to the statements detailed in the certification.