A solutions architect needs to continuously copy files from an Amazon S3 bucket to an Amazon EFS file system and to another S3 bucket. New files are added consistently to the source S3 bucket. Copied files should be overwritten only if the source file changes. Which solution meets these requirements with the LEAST operational overhead?

AWS DataSync is designed for automated, efficient, and secure data transfer between different storage services, including S3 and EFS. By creating DataSync locations for both the destination S3 bucket and the EFS file system, and then configuring tasks with the "transfer only data that has changed" option, DataSync automatically handles incremental transfers, ensuring only modified files are copied. This minimizes operational overhead compared to custom scripts or Lambda functions, as DataSync manages the infrastructure, retries, and monitoring. Incorrect options: A Lambda function would require custom code development, maintenance, and managing the function's execution environment, increasing operational overhead. Setting DataSync to "transfer all data" would copy all files every time, even if unchanged, leading to unnecessary data transfer and higher costs. An EC2 instance with a custom script requires managing the EC2 instance, developing and maintaining the script, and handling error conditions, which is significantly more operational overhead than DataSync.