Your company has strict requirements for data residency and needs to ensure that data in a Cloud Spanner database does not leave a specific region. How would you configure Cloud Spanner to meet this requirement?

*Explanation:* The best approach to meet the requirement of data residency in a specific region while using Cloud Spanner is to use a regional Spanner instance. A zonal instance is not officially supported and may not meet data residency requirements. A multi-region instance distributes data globally and cannot guarantee data residency. Implementing VPC Service Controls can limit access but does not ensure data residency. Cloud Data Loss Prevention (DLP) is not designed to enforce data residency and does not provide the required regional confinement.