Final answer:
The best source of historical evidence to learn about how an event unfolded is typically a primary source.
Step-by-step explanation:
The best source of historical evidence to learn about how an event unfolded is typically a primary source. Primary sources are objects or documents that come directly from the period being studied and provide firsthand information. Examples of primary sources include diaries, letters, government documents, photographs, and songs.
Option C, a newspaper account from when the event occurred, would be a primary source and could provide valuable information about the event. Option E, an oral history dictated two decades after the event, would also be a primary source, but there may be some limitations due to memory or potential bias.
Other options, such as a historical novel, a political map, or a research essay, would be considered secondary sources and may provide interpretations or analysis of the event but may not provide firsthand information about how it unfolded.