You must ensure legal-hold documents in a Cloud Storage bucket cannot be deleted or modified. What should you do?

Setting and locking a retention policy directly prevents objects from being deleted or modified for a specified duration, fulfilling the legal-hold requirement. Locking the policy ensures it cannot be reduced or removed. Setting a retention policy with an Archive storage class helps with cost-effective long-term storage but doesn't inherently prevent deletion or modification if the policy isn't locked. Object Versioning keeps multiple versions of an object, allowing recovery from accidental deletion or modification, but it doesn't prevent the current version from being deleted or modified, nor does it enforce a legal hold. A lifecycle rule automates version management but doesn't prevent deletion. Creating a copy in a different region provides disaster recovery but doesn't prevent deletion or modification of the original or the copy.