A company runs a web-front-end application on three Linux VMs behind an HTTP request–based load balancer in its on-premises data center. The application needs file storage for critical data. The company must migrate the app to AWS as quickly as possible and keep the AWS architecture highly available while making the FEWEST changes to the existing architecture. Which migration option satisfies these requirements with minimal architectural changes?

The correct option maintains the existing virtual machine (VM) architecture by migrating to Amazon EC2 instances, minimizing changes. Deploying across three Availability Zones with an Application Load Balancer ensures high availability. Amazon EFS provides a shared, highly available, and scalable file system that can be mounted by multiple EC2 instances, directly replacing the on-premises file storage without requiring application code changes. The incorrect options introduce significant architectural changes. ECS or EKS with Fargate (options 1 and 3) would require containerizing the application, which is a substantial change. S3 (option 1) is object storage, not a file system, and would require application modifications to use. FSx for Lustre (option 3) is a high-performance file system often used for HPC workloads, which is overkill and more complex for a typical web application's file storage needs. Migrating to three different AWS Regions (option 4) is a much larger architectural change than required for high availability within a single region and EBS volumes are block storage, not shared file storage, requiring complex replication or application-level synchronization.