How would the absence of each of the following factors affect the auditor's assessment of the control environment? Assume that the company's investment in marketable securities is material to the financial statements.

a. The board of directors is not actively involved in monitoring the company's policies regarding marketable securities.

b. The company has an internal audit department, but it does not have any computer audit expertise and has not conducted audits of the cash or marketable securities account during the past three years.

c. Management does not have written guidelines for investments in marketable securities. The financial executive has been successful in procuring good returns on investments in the past, and management does not want to tamper with success.