A company wants to build a new invoicing service for its cloud-native application on AWS. The company has a small development team and wants to focus on service feature development and minimize operations and maintenance as much as possible. The company expects the service to handle billions of requests and millions of new records every day. The service feature requirements, including data access patterns are well-defined. The service has an availability target of 99.99% with a milliseconds latency requirement. The database for the service will be the system of record for invoicing data. Which database solution meets these requirements at the LOWEST cost?