Final answer:
A Roman writing in 25 BCE about earlier events is considered a secondary source, which is any material written after the studied period that analyzes and interprets primary sources.
Step-by-step explanation:
A Roman writing in 25 BCE about events that happened centuries before would be considered a secondary source. A secondary source is a document, object, or other source material written or created after the time period under study. For instance, a twentieth-century biography of an Egyptian pharaoh is a secondary source, as it compiles, interprets, and analyzes historical evidence from primary sources. Similarly, the Roman's account from 25 BCE about earlier events falls into this category as it is not a direct witness or evidence from the time these events occurred. Instead, it provides the Roman's interpretation or synthesis of earlier events and is therefore one step removed from the primary source material. A primary source is an original document or object from the time period being studied, whereas a secondary source analyzes, interprets, or discusses something about primary sources.