Which AWS service should the company use to reduce management overhead for this environment?

Explanations:

Amazon Elastic Container Service (Amazon ECS) is primarily used for running and managing Docker containers. It is not designed for managing relational databases directly.

Amazon SageMaker is a machine learning service that provides tools for building, training, and deploying machine learning models. It is not relevant for database management.

Amazon RDS (Relational Database Service) is a managed database service that simplifies database setup, operation, and scaling. It provides automated backups, software patching, and scaling capabilities, making it ideal for migrating SQL Server databases to the cloud with reduced management overhead.

Amazon Athena is an interactive query service that allows users to analyze data in Amazon S3 using standard SQL. It is not designed for managing or hosting databases like SQL Server.