If a Company Has an Effective Internal Audit Department

Multiple Choice

If a company has an effective internal audit department,

A) the internal auditors can express an opinion on the fairness of the financial statements.
B) their work cannot be used by the external auditors per PCAOB Standard 5.
C) it can reduce external audit costs by providing direct assistance to the external auditors.
D) the internal auditors must be CPAs in order for the external auditors to rely on their work.