In every audit of financial statements in accordance with AICPA Professional Standards, an auditor must

a. Perform tests of controls to evaluate the effectiveness of the entity's accounting system.

b. Document his or her understanding of the client's internal control over financial reporting

c. Search for significant deficiencies in the operation of the internal control structure.

d. Implement improvements in internal control when deficiencies are discovered.

e. Determine whether control procedures will prevent or detect all material misstatements.