Which of the following is an example of unstructured data?

Unstructured data refers to information that does not have a pre-defined data model or structure, making it more challenging to collect, process, and analyze compared to structured data. Audio and video content are prime examples of unstructured data because they do not fit neatly into rows and columns like traditional data formats. Instead, they exist in formats that require advanced processing and analysis techniques, such as natural language processing or image recognition, to extract meaningful information.

The other examples provided—statistical reports, customer interviews, and transaction records—typically have a more organized format. Statistical reports contain structured data in a summarized manner, often based on computed values from datasets. Customer interviews can yield qualitative insights, but they usually require manual categorization to be effectively analyzed, while transaction records are often stored in databases with well-defined fields, categorizing information in a structured way. Thus, while these can have unstructured elements, they are primarily examples of structured or semi-structured data formats.