Which of the following best describes the function of a relational database?

Choosing the option that states a relational database connects tables of records using keys accurately captures the essential function of a relational database management system (RDBMS). In relational databases, data is organized into tables that can relate to one another through the use of primary and foreign keys. Primary keys uniquely identify records within a table, while foreign keys establish a relationship between tables, allowing data to be accessed and manipulated efficiently.

This structure enables complex queries and data retrieval across multiple tables, reflecting the relational model's power. It allows for normalization, preventing data redundancy and ensuring data integrity, which are key benefits of using relational databases.

The other options describe qualities that do not align with the core characteristics of relational databases. A flat file structure implies data is stored in a single table without relationships, hierarchical management is more characteristic of older database models, and while a multi-user environment is a feature of many databases, it does not specifically define the relational model's function or structure.