An organization is configuring an Azure Storage account to host business-critical application data. To ensure high availability, the architecture team establishes the following data resilience and governance requirements: Data must be protected against localized physical datacenter failures within the primary region. Data must be synchronously copied across three separate Azure availability zones. Data must not be replicated outside the primary region to comply with strict regional data residency regulations. Which Azure Storage redundancy option should the organization select?

Zone-redundant storage (ZRS): ### What Zone-Redundant Storage (ZRS) Is **Zone-redundant storage (ZRS)** is an Azure Storage redundancy option that synchronously replicates data across three separate Azure **availability zones** within the primary region. Each availability zone is an isolated physical datacenter location equipped with independent power, cooling, and networking infrastructure. ### How It Meets the Requirements - **Protects against datacenter failures**: Because data is distributed across three distinct availability zones, the failure of an entire physical datacenter does not cause data loss or outage for read/write operations. - **Synchronous replication**: ZRS writes synchronously across three availability zones in the primary region, ensuring consistent state and zero recovery point loss between zones. - **Regional data residency compliance**: All three copies stay entirely within the selected primary **Azure region**, ensuring adherence to strict governance and compliance policies regarding data sovereignty. ### Key Advantages and Capabilities - Provides **high availability** and resilience against datacenter-level disasters within a single geographic region. - Delivers at least **12 nines (99.9999999999%)** of data durability over a given year. - Allows applications to continue reading and writing data seamlessly even if an entire availability zone encounters an outage. - Eliminates the added latency and expense associated with cross-region geographic replication. ### Why This Is Optimal ZRS strikes the optimal balance between high resilience against datacenter outages and strict regional boundary compliance without introducing secondary region replication.