Amazon Aurora is a fully managed relational database engine that provides editions compatible with MySQL and PostgreSQL. This compatibility allows many existing applications, drivers, tools, and database skills associated with those open-source engines to be used with Aurora with limited or no modification. Therefore, option C is correct. Amazon Redshift is a managed cloud data warehouse designed primarily for analytics and large-scale SQL workloads. Although it uses SQL and is based on relational concepts, it is not the AWS database service described as MySQL- and PostgreSQL-compatible for transactional applications. Amazon DynamoDB is a serverless NoSQL key-value and document database and does not use the MySQL or PostgreSQL relational engines. Amazon Neptune is a managed graph database designed for highly connected datasets and supports graph query technologies rather than MySQL or PostgreSQL compatibility. The direct exam association is that Aurora is part of Amazon RDS and offers Aurora MySQL-Compatible Edition and Aurora PostgreSQL-Compatible Edition. It combines a managed cloud-native storage architecture with familiar relational database interfaces and compatibility.