Which of the Following Statements Best Describes the Auditor's Responsibility

Which of the following statements best describes the auditor's responsibility regarding the detection of fraud?

A) The auditor is responsible for the failure to detect fraud only when such failure clearly results from nonperformance of audit procedures specifically described in the engagement letter.
B) The auditor is required to provide reasonable assurance that the financial statements are free of both material errors and fraud
C) The auditor may extend auditing procedures to actively search for evidence of fraud where the examination indicates that fraud may exist.
D) The auditor is responsible for the failure to detect fraud only when an unqualified opinion is issued.