A company's audit shows that users have been changing cost-related tags on Amazon EC2 instances after deployment. The company has an organization in AWS Organizations with many AWS accounts.
The company needs a solution to detect the EC2 instances automatically. The solution must require the least possible operational overhead.
Which solution meets these requirements?

A. Use service control policies (SCPs) to track EC2 instances that do not have the required tags.
B. Use Amazon Inspector to run a report to identify EC2 instances that do not have the required tags.
C. Use an AWS Config rule to track EC2 instances that do not have the required tags.
D. Use AWS Well-Architected Tool (AWS WA Tool) to run a report to identify EC2 instances that do not have the required tags.