After how long must an appraiser retain his workfile, given the timeline of court proceedings discussed?

The requirement for an appraiser to retain their workfile is outlined in the Uniform Standards of Professional Appraisal Practice (USPAP). According to USPAP, an appraiser must retain their workfile for at least five years after the preparation of the report or until any relevant legal proceeding has been resolved, whichever period is longer.

The timeline mentioned in the question suggests a specific reference point for determining how long the appraiser's records must be maintained. If April 2016 aligns with a relevant deadline in the context provided (like the completion of a report or the resolution of a court proceeding), it becomes the correct answer for the time frame in which the appraiser is required to retain their workfile.

This alignment with the retention requirement illustrates the importance of keeping accurate records for future reference, especially in legal contexts, thereby supporting the necessity of compliance with USPAP guidelines.