The last option is timing.

Sampling Risk Read the overview below and complete the activities that follow When performing a test of controls, auditors must be concerned with two aspects of sampling risk: assessing control risk too high and assessing control risk too low. CONCEPT REVIEW: Assessing control risk too high is the risk that the sample results will cause the auditors to assess control risk higher than warranted based on the actual operating effectiveness of the control. Assessing control risk too low is the more important risk that the sample results will cause the auditors to assess risk at a lower level than warranted. Audit is affected when too much substantive testing is done. Audit effectiveness is impacted when the auditor doesn't do enough effectiveness efficiency evaluation opinion staff . An audit needs to have the correct balance of efficiency and Assessing the control risk too low results in an inappropriate of the extent of substantive procedures. . Auditors must carefully control the risk of assessing risk too high orwhen performing test of controls. timinn