Which of the following statements is true about a relational database?

A relational database is a collection of data items organized as a set of formally-described tables from which data can be accessed or reassembled in many different ways without having to reorganize the database tables. Answer: B is incorrect. The standard user and application program interface to a relational database is the structured query language (SQL). Answer: A is incorrect. In addition to being relatively easy to create and access, a relational database has the important advantage of being easy to extend. Answer: D is incorrect. A relational database is a set of tables containing data fitted into predefined categories. Each table (which is sometimes called a relation) contains one or more data categories in columns. Each row contains a unique instance of data for the categories defined by the columns.