The audit risk model is used to determine the required audit evidence based on the levels of inherent risk, control risk, and detection risk. The acceptable level of audit risk for ABC Limited is below or equal to 8%. Oliver identified both inherent risk (30%) and control risk (40%) while reviewing the company's financial statements. Using the audit risk model, he calculated the detection risk as 67%. The total audit risk was found to be 8%, which indicates that the auditors will fail to detect material misstatements in 67% of cases. The model highlights that control risk and inherent risk are independent of an auditor, whereas detection risk is dependent on the auditor's efforts.