An organization is required to provide assurance that its controls are properly designed and operating effectively. Which of the following reports will best achieve the objective?

An independent audit is the best choice because it provides a formal, objective evaluation of an organization's controls, including their design and operating effectiveness, typically against established standards or regulations. This process results in a report that offers assurance to stakeholders. Red teaming and penetration testing are offensive security exercises designed to identify vulnerabilities by simulating real-world attacks, but they don't provide a comprehensive assessment of control design or operating effectiveness across an entire control framework. A vulnerability assessment identifies security weaknesses but doesn't typically evaluate the effectiveness of existing controls or provide the same level of assurance as an independent audit.