Which of the following data collection strategies systematically tests the effects of various factors on an outcome?

Which of the following does not represent a difficulty in using red flags as fraud indicators?

An auditor used a questionnaire during an interview to gather information about the nature of credit sales processing. The questionnaire did not cover some pertinent information offered by the person being interviewed, and the auditor did not document the potential problems for further investigation.
The primary deficiency with the above process is that:

During an audit of a major metropolitan museum, an auditor was unable to locate selected items from the museum's collection. The director of the museum informed the auditor that the upcoming replacement of the museum's inventory tracking system would address the auditor's concerns. What follow-up activity should the auditor propose?

According to IIA guidance, organizations have the most influence on which element of fraud?