Under Sarbanes Oxley Act to what extent can the auditor rely on the tests of controls performed by the internal auditors to reduce their substantive testing?

Select one:

a. the external auditor has to test the work of the internal auditor to rely upon their work.

b. not acceptable for the external auditor to rely upon the work of the internal auditor.

c. the external auditor has to evaluate the competency and objectivity of the internal auditor in order to rely upon their work.

d. no restriction in relying upon the work of internal auditors.