A company runs its ERP system in the us-east-1 Region on Amazon EC2 instances. A public API on those instances lets customers exchange information with the ERP system. International customers report slow API response times. Which solution will improve response times for international customers MOST cost-effectively?

AWS Global Accelerator improves performance for global users by directing traffic to optimal AWS edge locations and then routing it over the AWS global network to the application endpoint. This minimizes latency for international customers accessing the ERP API in us-east-1. Direct Connect is for private, dedicated connections between on-premises and AWS, not for public API access from numerous international customers, and would be extremely costly and complex to implement for each customer. CloudFront is primarily a Content Delivery Network (CDN) for caching static and dynamic content, which might help with some API responses but Global Accelerator is designed for non-cacheable application traffic and provides network-level optimizations. AWS Site-to-Site VPN is for secure connections between networks, not for public API access, and would not inherently improve international latency more effectively than Global Accelerator.