The greatest concern for the risk practitioner when the potential vendor has offered to perform quarterly self-audits of its controls instead of having annual independent audits is that the controls may not be properly tested. Self-audits are audits that are performed by the vendor itself, without the involvement of an external or independent party. Self-audits may not be reliable, objective, or consistent, as the vendor may have biases, conflicts of interest, or lack of expertise in auditing its own controls. Self-audits may also not follow the same standards, criteria, or methodologies as independent audits, and may not provide sufficient assurance or evidence of the effectiveness of the controls. The other options are not as concerning as the possibility of improper testing of the controls, as they are related to the outcomes, expectations, or approaches of the controls, not the quality or validity of the controls. References = Risk and Information Systems Control Study Manual, Chapter 2: IT Risk Assessment, Section 2.3: IT Control Assessment, page 6