A company runs a heavily used web application on-premises where users upload media files to a file server. The application server is overutilized and uploads sometimes fail; the company frequently expands storage on the file server. They plan to migrate to AWS, want authenticated access for users across the US and Canada, will consider refactoring, and want to speed development with the least operational overhead. Which solution best meets these requirements?

The correct solution leverages AWS Amplify to rapidly develop a static website, fulfilling the desire for faster development and reduced operational overhead. Amplify Hosting integrates with CloudFront, providing global access and low latency for users across the US and Canada. Storing media in Amazon S3 directly addresses the storage expansion issue and offers a scalable, durable solution. Amazon Cognito provides robust, scalable user authentication. The other options are less optimal. Migrating the existing application server to EC2 with AWS Application Migration Service (AMS) still involves managing servers, increasing operational overhead. While S3 is used for storage, the core application remains server-based. Using IAM Identity Center for application sign-in is generally for AWS console/application access, not typically for end-user application authentication like Cognito. Building a static website with AppSync and Lambda is a viable serverless approach but Amplify simplifies and accelerates this development significantly, aligning better with the "speed development with least operational overhead" requirement.