Answer is c. concealment
Audit is an investigative method
used to find out if any facts are concealed. Hence answer is c).
Audit is not used for investigating theft and conversion. Audit is
also not used as investigating method for inquiry. An auditor is
bound to check accounting records based on evidence if any material
facts are misstated in financial statements and give his audit
opinion in the form of an audit report. If any facts are concealed
the auditor should bring the same to the attention of
management.