A company stores application data in many Amazon S3 buckets in one AWS account. Some of the S3 buckets contain sensitive data. The company does not have data inventory for the S3 buckets. The company uses server-side encryption with Amazon S3 managed keys (SSE-S3) to encrypt all data in the S3 buckets. A solutions architect must design a solution to encrypt sensitive data with a key that only administrators can access. Which solution will meet these requirements?