An ecommerce company runs a PostgreSQL database on an Amazon EC2 instance. The database stores data in Amazon Elastic Block Store (Amazon EBS) volumes. The daily peak input/output transactions per second (IOPS) do not exceed 15,000 IOPS. The company wants to migrate the database to Amazon RDS for PostgreSQL and to provision disk IOPS performance that is independent of disk storage capacity. Which solution will meet these requirements MOST cost-effectively?