A company wants to modernize a legacy batch processing system. The current system runs on a single on-premises server, processing files uploaded via SFTP. Processing a file takes between 5 and 10 minutes. The company wants a serverless architecture on AWS that scales automatically and minimizes operational overhead. Which architecture should the architect recommend?

Use AWS Transfer Family for SFTP to upload files to Amazon S3. Configure S3 Event Notifications to trigger an AWS Lambda function to process the file.

Deploy an EC2 instance running an SFTP server. Use a cron job to trigger a shell script that processes the files.

Use AWS Transfer Family for SFTP to upload files to Amazon S3. Configure S3 Event Notifications to trigger an AWS Step Functions state machine that runs an AWS Fargate task to process the file.

Use Amazon API Gateway to receive files and forward them to Amazon SQS. Use EC2 Auto Scaling to process the queue.