What characterizes a primary source?

A primary source is characterized by being an original document that contains personal observations, firsthand accounts, and direct evidence related to a specific event, topic, or period. This includes materials such as diaries, letters, photographs, official records, and artifacts. The key aspect of a primary source is its ability to provide direct insight into a subject from the perspective of someone who experienced or witnessed it, thereby offering unmediated access to the information.

In contrast, the other options represent secondary sources. An analysis of historic events conducted by an expert reflects the expert's interpretation and evaluation of primary sources rather than presenting firsthand evidence. A document that summarizes secondary findings compiles insights derived from other researchers' analyses, further distancing the information from the original events. Lastly, a summary of collective opinions on a topic aggregates views but lacks the primary data necessary to qualify as a primary source. Therefore, the correct option accurately encapsulates the essence of what defines a primary source.