The correct answer is C. flat-file.
A flat-file database is a database that stores data in a single table. This type of database is often used for small, simple applications. Flat-file databases are easy to create and manage, but they can be difficult to scale to large sizes.
A relational database is a database that stores data in multiple tables. Each table in a relational database represents a different entity, such as a customer or an order. The tables in a relational database are related to each other through common fields. Relational databases are more complex than flat-file databases, but they are also more powerful and flexible.
A large database is a database that contains a large amount of data. Large databases can be difficult to manage and maintain. They also require specialized hardware and software.
A DBMS (database management system) is a software application that allows users to create, manage, and access databases. DBMSs provide a number of features that make it easier to work with databases, such as data security, data integrity, and data recovery.
In conclusion, the correct answer to the question “This database has only one table” is C. flat-file.