Explanation: The rank-size rule defines range as the longest distance that a customer will travel to purchase a good or service. Threshold is the minimum market needed to support the supply of a product or service. It is assumed that customers which travel longer distances to purchase a higher-order good or service, and a provider of such goods and services will require a larger customer base to make a profit. Thus, higher-order services have larger ranges and thresholds.
The New River, rising on the Blue Ridge in North Carolina, runs northward and then turns westward across the Appalachian Valley and the Alleghenies (where it becomes the Kanawha River) and empties into the Mississippi River basin.
The one that is most likely study written records would be : C. Historians
The history of mankind started the moment we developed writing technique. With writing, we could get more accurate interpretation about what's been happening in the past