A company runs applications on Amazon RDS for PostgreSQL in us-east-1. Machine learning models generate near real-time reports using the same RDS database, which slows database performance during business hours. The company needs to improve database performance most cost-effectively. Which solution meets these requirements?

Creating a read replica in the same region (us-east-1) is the most cost-effective solution because it offloads read-heavy reporting queries from the primary database, improving its performance for transactional applications. Read replicas are designed for this exact purpose, providing an eventually consistent copy of the data for read operations. A cross-Region read replica would add unnecessary data transfer costs and increased latency, as the reporting application is likely in the same region. Multi-AZ deployment is for high availability and disaster recovery, not for offloading read traffic; the standby instance is not directly accessible for reads. AWS DMS is a migration service and while it could replicate data, it's an overly complex and potentially more expensive solution for simply offloading read queries compared to a native RDS read replica.