Final answer:
The correct option is d). Substantive procedures are not considered tests of controls; they are part of substantive testing, which aims to verify financial information rather than evaluate internal controls.
Step-by-step explanation:
Tests of controls in auditing are procedures to test the effectiveness of a company's internal control processes. The statement reads Tests of controls include all of the following except: a) Inquiry, b) Observation, c) Reperformance, d) Substantive procedures. Here, options a), b), and c) are all methods used to assess the effectiveness of internal controls, while option d) Substantive procedures are actually part of substantive testing, which focuses on the verification of financial statement balances and transactions, not on the processes of internal control. Hence, d) Substantive procedures is the correct answer as it is not a test of controls.