Which of the following is true of working papers?

Select one:

a. Working papers document the purpose of the control selected for testing and the conclusion made by the auditor, but not the results of the test.

b. Working papers document the results of the tests but not the purpose of the control selected for testing

c. Working papers are necessary for the junior auditor to keep track of the daily work, but are not important to the overall audit.

d. Working papers document the auditors' conclusion about control risk and the basis for that conclusion.