A company uses Amazon S3 as its data lake. A new partner must use SFTP to upload data files. A solutions architect needs to implement a highly available SFTP solution that minimizes operational overhead. Which solution will meet these requirements?

AWS Transfer Family directly supports SFTP and integrates seamlessly with Amazon S3, making it the most suitable solution for a highly available SFTP service with minimal operational overhead. It's a fully managed service, eliminating the need to provision or manage servers. The publicly accessible endpoint allows the partner to connect easily, and files are directly stored in the S3 data lake. Amazon S3 File Gateway is designed for on-premises applications to access S3, not as a direct SFTP server for external partners. EC2-based solutions, whether a single instance or load-balanced, require significant operational overhead for server management, patching, high availability, and custom SFTP server software, which contradicts the "minimize operational overhead" requirement. They also introduce complexity with VPNs or cron jobs for S3 integration.