A company runs an application on several Amazon EC2 instances that store persistent data on an Amazon Elastic File System (Amazon EFS) file system. The company needs to replicate the data to another AWS Region using an AWS-managed service. Which solution will meet these requirements MOST cost-effectively?

AWS Backup is the most cost-effective and AWS-managed solution for replicating EFS data to another Region. It provides a centralized, automated backup service that supports cross-Region replication natively for EFS, simplifying management and reducing operational overhead. The EFS-to-EFS backup solution is not a standard AWS-managed service for cross-Region replication; EFS replication is a built-in feature of EFS itself, but the phrasing "EFS-to-EFS backup solution" is not an official AWS service name. Running a nightly script to S3 and then using S3 Cross-Region Replication adds complexity and custom development, which is less cost-effective and managed than AWS Backup. Creating a cross-Region VPC peer and running rsync is a manual, complex, and resource-intensive solution that requires significant operational effort and does not leverage AWS-managed replication for EFS data.