Which AWS service should the company use to meet these requirements?

Explanations:

AWS Lambda is a serverless compute service that runs code in response to events and is not suitable for applications that require persistent instances with configurable CPU, memory, and storage.

Amazon Cognito is a service for user authentication and management. It does not provide infrastructure for deploying applications and is not relevant for migrating custom applications.

Amazon Athena is an interactive query service that allows analysis of data in Amazon S3 using SQL. It is not a compute service for deploying applications and therefore cannot meet the requirements specified.

Amazon EC2 (Elastic Compute Cloud) provides resizable compute capacity in the cloud. It allows users to launch instances with various configurations of CPU, memory, storage, and networking, making it suitable for migrating custom applications.