A company runs a batch application on Amazon EC2 instances with multiple Amazon RDS backend databases. The application is generating a high number of reads on the databases. A solutions architect must reduce database read load while ensuring high availability. What should the solutions architect do?

Adding Amazon RDS read replicas is the most effective solution for reducing read load on the primary database and ensuring high availability. Read replicas provide independent endpoints for read traffic, offloading the primary instance. They also enhance availability by allowing promotion to a standalone database in case of primary instance failure. Using Amazon ElastiCache for Redis or Memcached would require application-level changes to implement caching logic, which is not directly addressed by the question's focus on reducing database read load with existing architecture. While caching can reduce database reads, read replicas are a direct and immediate solution for scaling read capacity within RDS. Amazon Route 53 DNS caching caches DNS queries, not database queries, and therefore would not reduce the read load on the databases.