Your application utilizes Cloud Spanner for its database needs. You want to optimize costs while maintaining high availability. Which configuration would best meet these needs?

A multi-region instance provides high availability by distributing data across multiple geographical regions, ensuring resilience against regional outages. Committed-use pricing (CUP) offers significant cost savings compared to on-demand pricing, especially for stable, long-term workloads, directly addressing the cost optimization goal. A multi-region instance with on-demand pricing provides high availability but misses the cost optimization opportunity of CUP. A regional instance with read-only replicas improves read performance and some availability within a region but doesn't offer the same level of disaster recovery as a multi-region setup. A single-region instance with hourly pricing lacks both high availability and cost optimization. Automated backups are crucial for data recovery but don't inherently optimize ongoing costs or provide high availability in the same way as a multi-region deployment.