Which of the following is the BEST example of unstructured data?

A JSON file is considered semi-structured data because it uses tags and attributes to organize data, providing some structural elements without a rigid schema.

A relational database is an example of structured data, where data is organized into tables with predefined columns and rows, enforced by a strict schema.

A CSV file is considered structured data, as it organizes data into rows and columns with a consistent delimiter, allowing for easy parsing into a tabular format.

An audio file is an excellent example of unstructured data because it does not have a predefined format or schema, making it challenging to organize and process using traditional relational database methods. Its content consists of raw sound waves without inherent column or row structures.