Which of the following are currently available relational databases on Azure?

The correct answer is B, as it lists the current relational databases available on Azure. Azure SQL Database is a fully managed relational database service based on the latest version of Microsoft SQL Server. It provides high availability, automated backups, and scalability, making it suitable for a wide range of application scenarios.

Azure Database for MySQL is a managed database service for MySQL, providing features like scaling, security, and high availability. Similarly, Azure Database for PostgreSQL offers a fully-managed database service for the PostgreSQL database engine, which is popular for its advanced features and support for complex queries. Azure Database for MariaDB is also available, providing a managed service option for MariaDB, which is a popular fork of MySQL.

This option captures the full spectrum of popular open-source relational database engines available on Azure, allowing developers to choose the one that fits their needs while benefiting from Azure’s managed services capabilities.