An organization wants a cost-effective relational database (Digital Leader)

Correct answer: C) Cloud SQL.
Here's why:

A) Cloud Storage is a scalable object storage service suitable for storing large amounts of unstructured data, such as files and backups. However, it is not a relational database service and is not optimized for structured query operations typically associated with relational databases.

B) BigQuery is a fully managed data warehouse service designed for analyzing large datasets using SQL queries. While it is powerful for analytics, it is not a relational database service optimized for transactional workloads and may not be the most cost-effective option for that use case.

C) Cloud SQL is a fully managed relational database service that supports popular database engines such as MySQL, PostgreSQL, and SQL Server. It is designed for transactional workloads, offers high availability, automatic backups, and scalability, making it a cost-effective choice for organizations requiring a relational database solution without the overhead of managing infrastructure.

D) Dataflow is a fully managed stream and batch processing service for ingesting, transforming, and processing data in real-time. While it is useful for data processing tasks, it is not a relational database service and does not provide the features required for storing and querying relational data.