Answer: Create a read replica from the source DB instance. Serve read traffic from the read replica.

## Explanation The correct answer is **C** because: 1. **Read replicas are specifically designed for read scaling** - Amazon RDS read replicas allow you to offload read traffic from the primary database instance, which is the most effective way to handle increased read traffic. 2. **Multi-AZ standby replicas are for high availability, not read scaling** - Option A is incorrect because Multi-AZ standby replicas are synchronous replicas primarily used for failover purposes and cannot be used for serving read traffic (except for some specific database engines like Aurora). 3. **Transfer Acceleration is for S3, not RDS** - Option B is incorrect because Transfer Acceleration is an Amazon S3 feature that uses CloudFront's edge network to accelerate uploads to S3 buckets, not for RDS database performance. 4. **Kinesis Data Firehose is for data streaming, not database query optimization** - Option D is incorrect because Kinesis Data Firehose is used for loading streaming data into AWS data stores like S3, Redshift, or Elasticsearch, not for improving database query performance. ## Key AWS Concepts: - **RDS Read Replicas**: Provide read scaling by creating asynchronous copies of your primary database that can handle read-only queries. - **Multi-AZ Deployments**: Provide high availability through synchronous replication to a standby instance in a different Availability Zone. - **Read vs. Write Scaling**: Read replicas scale read operations, while write operations must go to the primary instance. - **PostgreSQL Support**: RDS for PostgreSQL supports read replicas, making this a valid solution for the described scenario. This solution effectively addresses the performance problems caused by increased read traffic while maintaining data consistency through asynchronous replication.

Author: LeetQuiz Editorial Team