正解:B
The business process supported by the system is the most important factor for an IS auditor to understand when planning an audit to assess application controls of a cloud-based system. An IS auditor should have a clear understanding of the business objectives, requirements, and risks of the process, as well as the expected outputs and outcomes of the system. This will help the IS auditor to determine the scope, objectives, and criteria of the audit, as well as to identify and evaluate the key application controls that ensure the effectiveness, efficiency, and reliability of the process. The other options are less important factors that may provide additional information or context for the audit, but not its primary focus. References:
* CISA Review Manual (Digital Version), Chapter 5, Section 5.31
* CISA Review Questions, Answers & Explanations Database, Question ID 212