Option B, AWS Data Lifecycle Manager, is the correct choice for implementing a data retention policy. It allows you to automate the process of transitioning and deleting data based on age or other criteria, ensuring that data is retained for the specified period and then deleted automatically. This service integrates with various AWS storage services, including Amazon S3, EFS, and FSx. While other options like versioning, Object Lock, and RDS backups have their use cases, they do not specifically address the data retention and automatic deletion requirements as effectively as Data Lifecycle Manager.