Which statement about extraordinary assumptions is true?

• A. They can be used in any assignment without disclosure.
• B. They do not require disclosure to the client.
• C. They should be used to speed up the process but not credibility.
• D. They may be used in an assignment only if they are required to develop credible results.

Answer: (D)

Extraordinary assumptions are beliefs about real-world conditions that, if later found false, could change the appraisal conclusions. They may be used only when necessary to produce credible results, and their use must be disclosed in the report (and to the client), with an explanation of how they affect the scope of work. This is why the correct idea is that they may be used in an assignment only if they are required to develop credible results. The other statements conflict with USPAP because extraordinary assumptions aren’t allowed to be used without disclosure, aren’t intended to speed up work, and aren’t permitted in any assignment without necessity.