A company plans to migrate its on-premises container infrastructure to AWS and wants to avoid unexpected administration and operational costs by moving toward a serverless model. Which AWS service best fits this requirement?

AWS Fargate is the correct choice because it is a serverless compute engine for containers, eliminating the need to provision, configure, and scale EC2 instances. This directly addresses the company's goal of avoiding unexpected administration and operational costs associated with managing servers. Amazon Connect is a cloud-based contact center service, unrelated to container infrastructure. Amazon Lightsail is a simplified virtual private server (VPS) service, offering pre-configured instances, but it still requires managing the underlying server. Amazon EC2 provides virtual servers that require manual provisioning, patching, and scaling, which goes against the serverless model and would incur significant administration and operational overhead.