Which statement best distinguishes between structured and unstructured data?

The correct statement is A.

• A. Structured data fits neatly in databases; unstructured data includes images, videos, and text. This option accurately describes the fundamental difference. Structured data is highly organized and formatted, making it easy to store in relational databases (like SQL tables) with predefined schemas. Examples include customer names, addresses, and transaction amounts. Unstructured data, on the other hand, lacks a predefined format or organization and does not fit into traditional databases. Common examples include emails, social media posts, images, audio files, and video files.

Options B, C, and D are incorrect because:

• B is incorrect; the security of data depends on the security measures implemented, not inherently on whether it is structured or unstructured.
• C is incorrect; both structured and unstructured data can contain qualitative (descriptive) and quantitative (numerical) information. The distinction is about organization, not data type.
• D is incorrect; encryption is a security practice that can be applied to both structured and unstructured data, and neither is always encrypted while the other is not.

The final answer is $\text{A}$.