Which of the following is a primary source?

• A. A peer-reviewed article interpreting a historical event
• B. A newspaper article analyzing the event
• C. The original diary written by a participant
• D. A textbook chapter summarizing the event

Answer: (C)

A primary source is a firsthand, direct record created at the time of the event by someone with direct experience or observation. The original diary written by a participant fits this definition because it comes from someone who witnessed or lived through what happened and records their own observations and thoughts without an intermediary interpretation.

The other options are secondary sources. They present analysis, interpretation, or summaries of events after they occurred, often drawing on multiple sources. A peer‑reviewed article interpreting a historical event, a newspaper article analyzing the event, and a textbook chapter summarizing the event all provide secondhand perspectives rather than the original, unfiltered account from someone who experienced it.