A financial services company on AWS designed security controls to meet NIST and PCI DSS standards. Third-party auditors need evidence that the controls are implemented and operating correctly across hundreds of AWS accounts in a single AWS Organizations organization. Which solution provides monitoring of the controls across accounts?

AWS Security Hub is the correct choice because it is designed to aggregate, organize, and prioritize security findings from various AWS services and partner products across multiple accounts. By designating a delegated administrator account, Security Hub can be enabled across all member accounts in an AWS Organization. It directly supports industry standards like NIST and PCI DSS through its security standards feature, providing a centralized view of compliance status. Amazon Inspector focuses on vulnerability management for EC2 instances and container images, not broad security control monitoring across an organization. Amazon GuardDuty is a threat detection service, not primarily for auditing compliance against standards. AWS CloudTrail records API activity and events, which can be used as input for compliance, but it doesn't inherently provide a consolidated view of compliance against specific standards like Security Hub does.