After obtaining an understanding of the companys internal control system, an auditor may decide to set control risk at the maximum level (i.e. take a substantive approach) for some assertions because he

a. Believes the internal controls are unlikely to be effective.

b. Determines that the pertinent internal control components are not well documented.

c. Performs tests of controls to restrict detection risk to an acceptable level.

d. Identifies internal controls that are likely to prevent material misstatements.