2. Charlotte and Ben, two new audit staff associates at Wallace CPA Firm and recent college graduates are discussing substantive testing and its relationship to audit sampling. There is some debate between the two as to what this relationship is, so they approach you, their supervisor, for explanation and clarification. Which of the below responses would be MOST appropriate to explain this relationship? a. Substantive testing is used to help the auditors determine what exactly to sample. In other words, substantive testing is used to determine the sample itself and the sample size. b. Substantive testing is really more focused on a client's system of internal control. Substantive testing is used more heavily in audits of private companies, as larger, publicly traded companies typically have well-developed systems of internal control which do not require sampling techniques. c. Substantive testing and audit sampling are related. Statistical audit sampling is used extensively by the auditors, however for cases when non-statistical sampling is more appropriate, the auditors will often perform substantive testing also to gain additional assurance. d. Substantive testing and audit sampling are related. The best way to think about it is that audit sampling is used to determine what items in