Which service should a solutions architect recommend to allow the application to copy files to AWS?

Explanations:

Amazon EFS is a scalable NFS file system, but it may not meet the requirement of a low-latency connection for SMB file shares and does not offer seamless integration with on-premises applications without code changes.

Amazon FSx for Windows File Server provides fully managed Windows file systems but requires code changes or SMB clients to be reconfigured, which contradicts the requirement of not modifying the application.

AWS Snowball is a physical data transport solution used for bulk data migration. It is not suitable for a daily ongoing file transfer requirement or for maintaining low-latency connections.

AWS Storage Gateway provides a hybrid cloud storage solution that allows on-premises applications to seamlessly store files in AWS with minimal changes. It supports SMB and can be configured to transfer files with low-latency.