Discrete variables produce discrete data that is...

Discrete variables are those that take on distinct or separate values, which are often countable. This means that they can only assume certain values and not any values within a range. For example, the number of aircraft on a base or the count of personnel in a squadron are typical examples of discrete variables.

The correct answer indicates that the data resulting from discrete variables can be enumerated or counted, meaning one can list the specific values without allowing for any intermediary values. In contrast, continuous variables would produce data that could include any number within a range, such as height or weight. The notion of discreteness is essential in statistics and data analysis as it informs appropriate methods of analysis and interpretation for such kinds of data.