As an auditor's reliance on the operating effectiveness of a control increases, what is expected?

When an auditor relies more heavily on the operating effectiveness of a control, the expectation is that they will obtain more reliable or extensive audit evidence supporting the effectiveness of that control. This is because a greater reliance on the control indicates that the auditor believes it is functioning correctly and contributes significantly to the reliability of financial reporting.

In this scenario, the auditor performs tests of controls and evaluates their effectiveness. If the auditor finds that the control is indeed effective, they can trust its operation, which reduces the need for, but does not entirely eliminate, extensive substantive testing in that area. Consequently, they may gather additional evidence to ensure the robustness of that reliance.

The fact that control risk is not fully eliminated is an important point, as it reinforces the idea that while reliance on a control can reduce the extent of other audit procedures, it doesn't negate the need to obtain sufficient and appropriate audit evidence. Other choices discuss aspects like the amount of evidence required or the degree of substantive procedures, which are contingent on the strength of the controls, but ultimately, the strong reliance implies the need for robust evidence to support that trust.