Answer: I would contend that the right answer is actually the B) A historian who wrote a book about politics in Jamestown during its founding period.
Explanation: Just to elaborate a little on the answer, it can be added that a source written by a person who lived at the time of the foundation of Jamestown—a blacksmith, an English sailor, and a person who helped organize the founding of the colony—is considered a primary source, since they were written at the time of the actual event, and, therefore, they can provide very valuable information. A book about politics in Jamestown during its founding period is, however, a secondary source, since it is an interpretation and an analysis of that event—the historian did not live at that time and was not an eyewitness.