Which statement best describes XML in terms of its origins and typical use?

Introduction / Context:
XML was designed to be both human-readable and machine-processable. It arose from SGML and found broad use in messaging, configuration, content management, and data interchange. Appreciating this breadth clarifies why XML remains foundational in many systems.

Given Data / Assumptions:

• Option (a) references XML’s lineage from SGML.
• Option (b) highlights XML’s dual life in documents and data.
• Option (c) emphasizes standardization and extensibility.

Concept / Approach:
XML is indeed a simplified subset of SGML. It is used widely for both document-centric workflows (publishing, DocBook, TEI) and data-centric exchanges (web services, configuration). It provides a standardized, extensible syntax for describing content—schemas or DTDs define the allowed structure and types.

Step-by-Step Solution:

Verification / Alternative check:
XML recommendations from W3C and real-world use in SOAP, RSS/Atom, XSL-FO, and configuration files demonstrate both document and data roles.

Why Other Options Are Wrong:
Choosing any single statement ignores valid aspects presented by the others. XML’s definition encompasses all three ideas.

Common Pitfalls:
Assuming XML is obsolete because of JSON’s popularity; XML persists where schemas, namespaces, and document workflows are critical.

Final Answer:
XML is all of the above.