The correct answer is to Use Amazon CloudFront with an S3 bucket as an origin. Amazon CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally with low latency and high transfer speeds. By using CloudFront with an S3 bucket, static assets are cached and served from edge locations closer to the users, thus reducing latency and load on the origin servers. CloudFront also optimizes the cost by reducing data transfer out of the S3 origin and through pricing tiers for various regions. Amazon RDS Multi-AZ is not suitable for static asset caching and does not provide the same level of global distribution and caching that CloudFront offers. Implementing an Auto Scaling group for EC2 instances does improve resilience but does not address the requirement for global performance optimization for static assets as effectively as CloudFront. AWS Global Accelerator improves internet traffic routing and optimizes for performance but is not designed specifically for static asset caching.