An application uses an Amazon EFS file system. A recent application bug corrupted several files, and the company wants a cost-effective way to back up and recover EFS so that individual files can be restored quickly. Which option best satisfies these requirements at the lowest cost?

The correct option is to use AWS Backup for the EFS file system to store backups in a backup vault and perform partial-restore jobs to restore individual files. AWS Backup provides a centralized, automated backup service that supports EFS. It allows for granular, file-level restores directly from the backup vault, which is crucial for quick recovery of individual corrupted files. This approach is cost-effective because you only pay for the backup storage and data transfer, and it avoids the complexities and higher costs of managing a separate EFS file system or the slower retrieval times of Glacier for frequent individual file restores. Configuring Amazon Data Lifecycle Manager to archive to S3 Glacier is incorrect because DLM is primarily for EBS snapshots, not EFS, and Glacier retrievals are too slow for quick individual file recovery. Creating a second EFS in another region with DataSync is incorrect because it's a more expensive solution for continuous replication rather than point-in-time backups, and maintaining a second active EFS is costly. Enabling AWS Backup to an S3 Glacier vault is incorrect because while AWS Backup supports EFS, directly backing up to Glacier would incur significant retrieval costs and delays for individual file restores, which contradicts the "quick restore" requirement.