The correct answer is D. Reflex.
A relational database is a database management system (DBMS) that stores and retrieves data as a series of formally described tables from which data can be accessed or reassembled in many different ways without having to reorganize the database tables.
dBASE IV, 4th Dimension, and FoxPro are all relational databases. Reflex is a hierarchical database, which is a type of database that stores data in a tree-like structure.
In a hierarchical database, each record can have only one parent record. This means that the data is not as flexible as it is in a relational database, where each record can have multiple parent records.
Hierarchical databases are typically used for applications that require a lot of data to be stored in a specific order, such as inventory management systems.
Relational databases are typically used for applications that require a lot of flexibility in how the data is stored and retrieved, such as customer relationship management (CRM) systems.