In data classification, which of the following is a typical example of structured data commonly stored in relational databases?

Introduction / Context:
Data is often categorized as structured, semi-structured, or unstructured. Relational databases excel at storing structured data that fits predefined schemas and data types, enabling efficient querying and constraints.

Given Data / Assumptions:

• Structured data conforms to fixed columns and data types.
• Unstructured data includes media like images and videos.
• We are comparing examples that either fit or do not fit fixed schemas.

Concept / Approach:
Dates are classic structured data: they have standardized formats, clear validation, and indexing possibilities. They support comparisons, ranges, and arithmetic (e.g., date difference) in SQL.

Step-by-Step Solution:

Verification / Alternative check:
SQL dialects have native DATE/DATETIME types with constraints, functions, and indexes, confirming structured nature.

Why Other Options Are Wrong:
Photo image and video clip are unstructured (or at best semi-structured via metadata).
None of the above is incorrect because dates are valid structured data.

Common Pitfalls:
Confusing storage method (e.g., storing a file path) with data classification; the media itself is unstructured even if referenced structurally.

Final Answer:
Dates