Which of the following statements related to auditor independence is INCORRECT (or least appropriate)?

Select one:

a. An auditor may serve on the board of directors of a firm that is an audit client.

b. An auditor who is an immediate family member of a director or senior executive of an audit client must not be assigned to the audit team.

c. Purchasing goods from an audit client on normal commercial terms via an arm's length transaction does not create a threat to the auditors independence.

d. An auditor who was recently a director of of an audit client must not be assigned to the audit team for that client.