AWS Certified DevOps Engineer - Professional DOP-C02

A company uses an AWS Organizations organization to manage its 500 AWS accounts. All features are enabled in the organization, and the AWS accounts reside in a single OU. Developers must use the CostCenter tag key for every resource in the organization's member accounts. Some teams do not use the CostCenter tag key when tagging their Amazon EC2 instances.

The cloud team created a script that scans all EC2 instances in the organization's member accounts. When an EC2 instance lacks a CostCenter tag key, the script notifies the AWS account administrators. To prevent receiving this notification, some developers apply the CostCenter tag key with an arbitrary string as its tag value.

The cloud team must ensure that every EC2 instance in the organization uses a CostCenter tag key with the correct cost center value.

Which solution meets these requirements?