According to IIA guidance, which of the following scenarios demonstrates an internal auditor exercising due professional care?

When auditing investments, the auditor identified instruments with which he was unfamiliar. He decided not to select that type of investment in his sample, as he did not have the knowledge needed to A. perform a proper assessment.

B. An auditor was reviewing inventory counts conducted by the warehouse staff. One truck containing an immaterial amount of inventory was off-site and wasn't verified by the auditor.

C. An auditor visited a plant that produces a significant portion of the organization's inventory. The day he arrived, the plant manager was out sick, so the auditor issued the report without interviewing the manager.

D. An auditor in charge needed to have testing completed by the end of the month, but was behind schedule. He identified a junior auditor to conduct the work for him on a complex area of the organization.