A company uses an Amazon S3 bucket to integrate multiple data sources into a central...

Option B is most cost-effective because it combines a serverless ETL service for overnight processing with a serverless warehouse for partner SQL access during business hours. The material describes AWS Glue as a “fully managed, serverless, scalable ETL service” that can extract, transform, and load data with minimal operational overhead, which fits the requirement for multiple transformations and data cleaning.

For the SQL access layer, the study material highlights the cost advantage of Amazon Redshift Serverless: it automatically provisions and scales capacity and you pay only for the compute capacity provisioned, with no compute costs when no workloads are running. That directly supports “multiple business partners” querying during business hours while avoiding the always-on cost of a provisioned cluster.

Options C and D use a provisioned Redshift cluster, which is less cost-effective because capacity must be paid for even when partners are not querying. Option A adds EMR cluster management cost and operational overhead compared to using Glue for ETL.