Which of the Following Statements Concerning the Auditor's Use of the Work

Which of the following statements concerning the auditor's use of the work of an expert is correct?

A) If the auditor believes that the determinations made by the expert are unreasonable, only an adverse opinion may be issued.
B) If the expert is related to the client, the auditor is not permitted to use the expert's findings as corroborative evidence.
C) The expert should be identified in the auditor's report if the auditor has relied on the expert in issuing an unmodified auditor's opinion.
D) The expert should have an understanding of the auditor's corroborative use of the expert's findings.