Which of the following is an example of a primary source?

A primary source is an original document or artifact created at the time of an event or a first-hand account of an experience. A diary or historical document is a direct representation of an individual's thoughts, experiences, or observations during a specific time period. This makes it invaluable for researchers and historians seeking to understand the context and details of that era or event.

In contrast to primary sources, secondary sources, such as a biography or textbook, interpret, analyze, or summarize information derived from primary materials. These provide valuable context and analysis but do not serve as direct evidence of the time or event in question. Similarly, a documentary film, while it may include primary source material, is ultimately a constructed narrative that synthesizes information rather than presenting it in its raw form. Thus, the diary or historical document stands out as the primary source in this context.