A financial services company launched a new application that uses an Amazon RDS for MySQL database. The application runs only 2 hours at the end of each week. The company needs to minimize the cost of running the database. Which solution meets these requirements MOST cost-effectively?

Aurora Serverless v2 is the most cost-effective solution because it automatically scales capacity up and down based on application demand, and you only pay for the database capacity you consume. Since the application runs only 2 hours per week, Aurora Serverless v2 will scale down to a minimal capacity (or even pause if no connections are active), significantly reducing costs compared to a continuously running provisioned instance. Migrating to a regular Aurora MySQL database cluster would still incur costs for provisioned instances even when not in use. Migrating to an EC2 instance with a reservation would require managing the database yourself and paying for the instance even when idle, negating the cost savings for intermittent use. Using ECS with MySQL containers would also require managing the database and underlying infrastructure, and would likely incur higher operational overhead and potentially higher costs for intermittent use compared to Aurora Serverless v2.