Amazon Athena Overview:

Amazon Athena is a serverless query service that allows users to analyze data in S3 using standard SQL.

It is commonly used to query AWS Cost and Usage Reports stored in S3.

How It Works for Cost Reports:

Cost and Usage Reports are delivered in a structured format to an S3 bucket.

Athena can query these reports without requiring additional ETL processes.

Why Other Options Are Incorrect:

A. Amazon OpenSearch Service:Designed for search and log analytics, not querying structured data.

C. Amazon Aurora:A relational database service, unsuitable for querying S3 data directly.

D. AWS Glue:Used for ETL tasks but not directly for querying.