During the audit of a large manufacturing company, the auditor did not observe all locations of physical inventory. The auditor chose a random number of sites to visit, and the company's internal auditors visited the other sites. The auditor has confidence in the competence and objectivity of the internal auditors. The auditor personally observed only about 20% of the total inventory, but neither the auditor nor the internal auditors noted any exceptions in the inventory process.

a) unqualified opinion, with no report modifications

b) unqualified opinion with report modification

c) qualified opinion

d) disclaimer of opinion

e) adverse opinion