Answer: Create an Amazon RDS database with Multi-AZ DB cluster deployment.

## Explanation The correct answer is **C. Create an Amazon RDS database with Multi-AZ DB cluster deployment.** Let's analyze each option: **A. Create an Amazon DynamoDB database table configured with global tables.** - **Problem**: The requirement specifies PostgreSQL database engine. DynamoDB is a NoSQL database, not PostgreSQL. - **Global tables** provide multi-region replication but don't meet the PostgreSQL requirement. **B. Create an Amazon RDS database with Multi-AZ deployments.** - **Provides high availability** through synchronous replication to a standby instance in another Availability Zone. - **Limitation**: Only provides a single standby instance for failover, not for read scaling. - **Doesn't address read workload scaling** - the standby instance cannot be used for read operations in standard Multi-AZ deployments. **C. Create an Amazon RDS database with Multi-AZ DB cluster deployment.** - **✓ Provides high availability** with three instances across three Availability Zones. - **✓ Supports read scaling** - includes two readable standby instances that can handle read queries. - **✓ Most operationally efficient** because it combines high availability with read scaling in a single deployment. - **✓ Specifically designed for PostgreSQL** and MySQL with Aurora storage. **D. Create an Amazon RDS database configured with cross-Region read replicas.** - **Provides read scaling** through read replicas in another region. - **Provides disaster recovery** but not local high availability. - **Less operationally efficient** than Multi-AZ DB cluster because: - Cross-region replication adds latency - More complex to manage across regions - Higher costs for cross-region data transfer - Doesn't provide automatic failover within the primary region **Key Points**: - **Multi-AZ DB cluster** deployment provides both high availability (automatic failover) and read scaling (two readable standby instances). - This is the most operationally efficient solution as it addresses both requirements in a single, integrated architecture. - The company's application is already in a single AWS Region, so cross-region solutions add unnecessary complexity.

Author: LeetQuiz Editorial Team