You need a globally distributed, relational store that provides identical state to all clients and supports multi-region deployment with low latency. Which storage should you use?

Cloud Spanner is the correct choice because it is a globally distributed, strongly consistent, relational database service that offers transactional consistency across regions and continents. Its architecture provides low-latency reads and writes globally, ensuring identical state for all clients. Cloud Bigtable is a wide-column NoSQL database, not relational, and lacks strong global consistency. Cloud SQL is a regional relational database, not globally distributed with strong consistency across regions. Firestore is a NoSQL document database, not relational, and while it offers global distribution, its consistency model differs from Spanner's strong global transactional consistency.