From a Document Understanding perspective, what kind of document is the one below?

Understanding Semi-Structured Documents:

Semi-structured documents, such as invoices, contain a mix of fixed fields (e.g., "Invoice #", "Date", "Total Due") and variable content (e.g., line items or descriptions).

The layout is consistent, but the number of items or specific details can vary between documents.

Analysis of the Provided Example:

The invoice contains a structured header with fields like "Invoice #", "Date", and "Due Date".

The line items section varies depending on the products and quantities.

Option Analysis:

Structured (B): Incorrect, as fully structured documents have fixed layouts with no variability.

Fixed structured format (C): Incorrect, as the variability in line items disqualifies this.

Semi-unstructured (D): Incorrect, as this refers to documents with highly variable layouts like free-form emails.

Correct Option (A): Invoices are classic examples of semi-structured documents​​.