You want to analyze large datasets using SQL queries. Which service is most appropriate?

Correct answer: BigQuery

Option B is correct because BigQuery is Google Cloud's fully managed, serverless data warehouse designed for running fast SQL analytics on datasets ranging from gigabytes to petabytes, making it the natural choice for large-scale SQL query analysis. Option A is wrong because Firestore is a NoSQL document database optimized for transactional reads and writes in mobile and web applications, not for complex analytical SQL queries over large datasets. Option C is wrong because Cloud Spanner is a globally distributed relational database suited for transactional OLTP workloads requiring strong consistency, not primarily for large-scale analytical queries. Option D is wrong because Cloud Bigtable is a NoSQL wide-column store optimized for high-throughput time-series and IoT data, and it does not support standard SQL analytics natively.