A post-implementation RCSA is a process of verifying whether the risk treatment plan has been executed as intended and whether the residual risk is within the acceptable level. It involves testing the effectiveness of the controls that have been implemented to mitigate the risk and identifying any gaps or issues that need to be addressed. A BIA, the original risk response plan, and the training program and user awareness documentation are not sufficient to validate the effectiveness of the risk treatment plan, as they do not measure the actual performance of the controls or the residual risk.
References:
*ISACA, Risk IT Framework, 2nd Edition, 2019, p. 761
*ISACA, Risk and Information Systems Control Review Manual, 7th Edition, 2020, p. 2112

The number of projects going live without a security review is the best key control indicator (KCI) to indicate whether security requirements are identified and managed throughout a project life cycle, because it measures the compliance and effectiveness of the security review process. A security review is a process that ensures that the security requirements are defined, implemented, tested, and verified for each project, and that any security risks or issues are identified and resolved before the project is deployed. The number of projects going live without a security review should be minimized or eliminated, as it indicates a failure or weakness of the security review process. The other options are not the best KCIs, because they do not directly measure the identification and management of security requirements. The number of employees completing project-specific security training, the number of security projects started in core departments, and the number of security-related status reports submitted by project managers are examples of input or output indicators that measure the activities or results of the project, but not the security requirements. References = CRISC:
Certified in Risk & Information Systems Control Sample Questions

A third-party security assessment report is the most helpful to ensure effective security controls for a cloud service provider, because it provides an independent and objective evaluation of the cloud provider's security posture, policies, and practices. A third-party security assessment report can help to verify and validate the cloud provider's compliance with the relevant standards, regulations, and best practices, such as ISO 27001, PCI DSS, NIST, or CSA. A third-party security assessment report can also help to identify and address any gaps, weaknesses, or vulnerabilities in the cloud provider's security controls, and to provide recommendations and guidance for improvement. A third-party security assessment report can also help to increase the trust and confidence of the cloud customers, and to facilitate the due diligence and risk management processes. The other options are less helpful to ensure effective security controls for a cloud service provider. A control self-assessment is a process that enables the cloud provider to assess its own security controls, using a predefined framework or questionnaire. However, a control self-assessment may not be as reliable or comprehensive as a third-party security assessment report, as it may be biased, incomplete, or inaccurate, and it may not cover all the aspects or dimensions of security. Internal audit reports from the vendor are documents that provide the results and findings of the internal audits conducted by the cloud provider's own auditors, to verify and validate the effectiveness and efficiency of the security controls. However, internal audit reports from the vendor may not be as credible or trustworthy as a third-party security assessment report, as they may be influenced by the cloud provider's interests, objectives, or agenda, and they may not follow the same standards or criteria as the external auditors. Service level agreement monitoring is a process that measures and evaluates the performance and availability of the cloud services, based on the predefined metrics and targets agreed between the cloud provider and the cloud customer. However, service level agreement monitoring may not be sufficient or relevant to ensure effective security controls for a cloud service provider, as it may not address the security aspects or requirements of the cloud services, such as confidentiality, integrity, or accountability, and it may not reflect the actual security risks or incidents that may occur in the cloud environment. References = Cloud Security Controls: Key Elements and 4 Control Frameworks 1

The best way to test the operational effectiveness of a data backup procedure is to perform a complete restoration of every file to a clean system and verify that there has not been any data corruption or loss. This will ensure that the backup procedure can successfully recover the data in the event of a disaster or incident.
The other options are not sufficient to test the operational effectiveness of a data backup procedure, as they do not involve actually restoring the data and verifying its integrity and usability. References = How to review and test backup procedures to ensure data restoration; HOW TO TEST DATA BACKUPS: A BRIEF GUIDE; How to Test a Database Backup

Infrastructure as a Service (IaaS) provides organizations with the highest level of control over their IT resources in the cloud. With IaaS, clients manage the operating systems, storage, deployed applications, and possibly limited control of select networking components. This level of control allows organizations to manage the data life cycle comprehensively, including data creation, storage, processing, and disposal. In contrast, PaaS and SaaS models abstract more of these controls, limiting the client's ability to manage the data life cycle directly.
Reference:ISACA CRISC Review Manual, 7th Edition, Chapter 4: Information Technology and Security, Section: Cloud Computing Models.