A company wants to migrate a Microsoft SQL Server database server from an on-premises data...

Amazon EC2 allows you to install and manage SQL Server directly on a Windows or Linux VM, giving you full access to the underlying operating system. This is required when you need to install custom agents, configure OS-level features, or have complete control over the environment.

Amazon RDS and Aurora are managed services and do not provide access to the underlying OS, nor does Redshift (which is a data warehouse, not SQL Server).

AWS Documentation Extract:

" If you require access to the underlying operating system or need to install custom software, use SQL Server on Amazon EC2. Amazon RDS is a managed service and does not provide OS-level access. "

(Source: AWS Database Migration documentation, SQL Server Deployment Options)