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

Explanations:

Amazon RDS is a managed relational database service that requires provisioning and managing infrastructure. It is not designed for querying data stored in S3 directly using SQL without setting up a database instance.

Amazon Redshift is a data warehouse service that requires setting up a cluster and managing it. It is not suitable for querying S3 data without infrastructure setup, though it can integrate with S3 after configuration.

Amazon Athena is a serverless interactive query service that allows users to analyze data in S3 using standard SQL without the need to set up or manage any infrastructure. It is designed for ad-hoc querying of large datasets stored in S3.

Amazon EC2 provides virtual servers in the cloud and requires users to set up and manage infrastructure. It is not a query service for S3 data and does not provide direct SQL querying capabilities without additional configuration.