A company runs an ecommerce application where each new order is published to a RabbitMQ queue on an Amazon EC2 instance in a single Availability Zone. A separate EC2 instance processes messages and stores details in a PostgreSQL database on another EC2 instance. All EC2 instances are in the same Availability Zone. The company wants the highest availability with the least operational overhead. What should a solutions architect do?

The correct option provides the highest availability with the least operational overhead. Amazon MQ offers managed RabbitMQ with active/standby redundancy, eliminating the need to manage EC2 instances for the queue. A Multi-AZ Auto Scaling group for the application EC2 instances ensures high availability and automatic scaling. Migrating the database to a Multi-AZ Amazon RDS for PostgreSQL deployment provides automatic failover, backups, and patching, significantly reducing operational overhead compared to managing PostgreSQL on EC2 instances. The other options involve managing RabbitMQ or PostgreSQL on EC2 instances, which increases operational overhead. Creating Multi-AZ Auto Scaling groups for RabbitMQ or PostgreSQL EC2 instances still requires managing the underlying software, patching, and backups, which is less efficient than using managed services like Amazon MQ and Amazon RDS.