A company moved its on-premises PostgreSQL database to an Amazon RDS for PostgreSQL DB instance. The company successfully launched a new product. The workload on the database has increased. The company wants to accommodate the larger workload without adding infrastructure. Which solution will meet these requirements MOST cost-effectively?

• ABuy reserved DB instances for the total workload. Make the Amazon RDS for PostgreSQL DB instance larger.
• BMake the Amazon RDS for PostgreSQL DB instance a Multi-AZ DB instance.
• CBuy reserved DB instances for the total workload. Add another Amazon RDS for PostgreSQL DB instance.
• DMake the Amazon RDS for PostgreSQL DB instance an on-demand DB instance.