6. Which of the following statements is true? a. Tests of controls are not a form of audit evidence. b. With good results from tests of controls, an auditor will most likely increase the level of substantive testing of transactions and balances. c. Where the auditor decides to use a substantive approach to obtaining evidence, it is not necessary to obtain an understanding of internal controls to assess the risk of possible financial statement misstatements. d. If the preliminary assessment of internal controls suggests that controls cannot be relied on, the auditor should go straight to performing substantive testing