A company has a web application with sporadic usage: heavy at the start of each month, moderate at the start of each week, and unpredictable during the week. The application uses a web server and a MySQL database server in a data center. The company wants to move to AWS and choose a cost-effective database platform that requires no database modifications. Which solution meets these requirements?

MySQL-compatible Amazon Aurora Serverless is the most cost-effective and suitable solution. Aurora Serverless automatically scales database capacity up and down based on demand, eliminating the need for manual provisioning and reducing costs during periods of low usage. Its MySQL compatibility ensures no database modifications are required. Amazon DynamoDB is a NoSQL database, requiring significant application and database modifications, which violates the requirement. Amazon RDS for MySQL is a good option for managed MySQL, but it still requires pre-provisioning capacity, making it less cost-effective than Serverless for sporadic workloads. MySQL on Amazon EC2 with Auto Scaling is a self-managed solution, incurring operational overhead and not being as cost-effective or hands-off as Aurora Serverless.