A company has a web application with an embedded NoSQL database. The application runs on Amazon EC2 instances behind an Application Load Balancer (ALB). The instances are in an Auto Scaling group in a single Availability Zone. Traffic has increased and the application must be highly available; the database can be eventually consistent. Which solution meets these requirements with the LEAST operational overhead?

The correct solution addresses both high availability for the application and the database with minimal operational overhead. Modifying the Auto Scaling group to use EC2 instances across three Availability Zones ensures application high availability and fault tolerance, as traffic can be distributed and instances replaced if an Availability Zone becomes unhealthy. Migrating the embedded NoSQL database to Amazon DynamoDB provides a fully managed, highly available, and scalable NoSQL database service that supports eventual consistency. AWS DMS simplifies the migration process. Incorrect options: Replacing the ALB with an NLB doesn't address the single Availability Zone limitation for high availability and doesn't improve the database's operational overhead or scalability. Migrating the database to DynamoDB is good, but keeping the application in a single AZ doesn't meet the high availability requirement for the entire solution. Maintaining the embedded NoSQL database and its replication service on EC2 instances across multiple AZs increases operational overhead for managing database replication and scaling compared to a fully managed service like DynamoDB.