A company sells large datasets stored in an Amazon S3 bucket in the us‑east‑1 Region. A web app on multiple Amazon EC2 instances behind an Application Load Balancer issues S3 signed URLs after purchase so customers can download datasets. Customers are located across North America and Europe. The company wants to reduce data transfer costs while maintaining or improving performance. What should a solutions architect recommend?

Deploying an Amazon CloudFront distribution with the S3 bucket as the origin is the best solution. CloudFront is a Content Delivery Network (CDN) that caches content at edge locations geographically closer to users, significantly reducing latency and improving download performance for customers across North America and Europe. By serving data from edge locations, CloudFront also reduces data transfer costs from S3, as egress charges from S3 to CloudFront are typically lower than direct S3 egress to the internet. Switching to CloudFront signed URLs maintains secure access control. S3 Transfer Acceleration can improve upload performance but offers less benefit for downloads compared to CloudFront's global caching. Setting up Cross-Region Replication would incur additional storage and replication costs and still wouldn't provide the global caching benefits of a CDN for all users. Streaming data through the web application would increase EC2 instance load and egress costs from EC2, rather than reducing them.