Which AWS service lets you obtain compliance and audit reports on demand?

AWS Artifact is the correct answer because it is a central resource for on-demand access to AWS security and compliance reports and select online agreements. This service helps customers understand and verify the security and compliance posture of AWS. AWS Secrets Manager securely stores and manages secrets like API keys and database credentials, not compliance reports. AWS Security Hub provides a comprehensive view of your security alerts and security posture across your AWS accounts, but it doesn't provide the compliance reports themselves. AWS Certificate Manager provisions, manages, and deploys SSL/TLS certificates for use with AWS services, which is unrelated to compliance and audit reports.