55. Internal auditors must determine appropriate and sufficient resources to achieve engagement objectives. When determining the necessary resources needed to perform an engagement, which of following should the auditor consider? I. The number and experience of the auditing staff. 11. Knowledge, skills and other competencies of the auditing staff. 111. Proper sampling technique. IV. Probability of errors, irregularities, noncompliance and other exposures. a. I and II only. b. I and 1V only. c. II and III only. d. III and IV only