Which of the following describes a common characteristic of flat files?

Flat files are typically characterized by their simplicity in storing data, which is often represented in a plain text format. This format allows data to be easily viewed and edited using standard text editors, making flat files user-friendly and accessible. The data is usually structured in a straightforward manner, often organized in rows and columns, without complex structures or relationships that more sophisticated databases might utilize.

The other options describe characteristics that do not align with the nature of flat files. For instance, flat files lack a relational structure, meaning they do not inherently support relationships between different pieces of data, unlike relational databases. They also do not accommodate complex data types as effectively as other data storage systems, which are designed to handle more intricate datasets. Furthermore, flat files do not automatically enforce data integrity; this means that while users can add data freely, there are no built-in mechanisms to prevent data inconsistencies, which is often essential in maintaining accurate and reliable databases.

Therefore, the defining characteristic of flat files is their use of a plain text format for data storage, which embodies their simplicity and ease of use.