A company needs a solution that restricts access to Amazon S3 data and encrypts the...

Option B is correct because IAM policies are the standard AWS mechanism to control access to Amazon S3, and SSE-KMS encrypts S3 data with AWS KMS keys. AWS S3 documentation for SSE-KMS explains that it uses AWS Key Management Service keys for server-side encryption, and Secrets Manager documentation states that you can store secrets securely and configure automatic rotation. AWS further explains that rotation updates the credentials in both the secret and the target database or service, and that Secrets Manager uses a Lambda rotation function for supported rotation patterns.

Option A is weaker because Lambda environment variables are not the right service for managed secret storage and automatic rotation. Option C is not the best answer because S3 ACLs are not the preferred modern access-control model compared with IAM and bucket policies, and Parameter Store is not the main AWS service for built-in managed database credential rotation. Option D uses SSE-S3, not KMS-based encryption, and relies on a custom rotation approach instead of the native managed secret-rotation service. The study guide also highlights AWS KMS for encryption-key management and Secrets Manager for rotating credentials.