Performing a post-implementation review is the best way to confirm whether appropriate automated controls are in place within a recently implemented system, as it helps to evaluate the effectiveness and efficiency of the system and its controls after they have been deployed and operationalized. A post-implementation review is a process of assessing and validating the system and its controls against the predefined criteria and objectives, such as functionality, performance, security, compliance, and user satisfaction. A post-implementation review can help to confirm whether appropriate automated controls are in place within a recently implemented system by providing the following benefits:

It verifies that the system and its controls meet the design specifications and standards, and comply with the relevant laws, regulations, and contractual obligations.

It identifies and measures the actual or potential benefits and value of the system and its controls, such as improved efficiency, reliability, or quality.

It detects and analyzes any issues, gaps, or weaknesses in the system and its controls, such as errors, inconsistencies, or vulnerabilities.

It provides recommendations and action plans to address the identified issues, gaps, or weaknesses, and to improve or enhance the system and its controls.

It communicates and reports the results and findings of the review to the relevant stakeholders, and solicits their feedback and suggestions.

The other options are not the best ways to confirm whether appropriate automated controls are in place within a recently implemented system. Conducting user acceptance testing is an important step to ensure that the system and its controls meet the user requirements and expectations, but it is usually performed before the system is implemented and operationalized, and it may not cover all aspects of the system and its controls. Reviewing the key performance indicators (KPIs) is a useful method to measure and monitor the performance of the system and its controls, but it may not provide a comprehensive or objective evaluation of the system and its controls. Interviewing process owners is a possible technique to collect and analyze information on the system and its controls, but it may not provide sufficient or reliable evidence to confirm the appropriateness of the system and its controls. References = Post-Implementation Review: The Key to a Successful Project, IT Risk Resources | ISACA, Post Implementation Review (PIR) - Project Management Knowledge