A company runs an application on Amazon EC2 instances that have instance store volumes attached. The application uses Amazon Elastic File System (Amazon EFS) to store files that are shared across a cluster of Linux servers. The shared files are at least 1 GB in size. The company accesses the files often for the first 7 days after creation. The files must remain readily available after the first 7 days. The company wants to optimize costs for the application. Which solution will meet these requirements?