What is the purpose of the discussion of the "flour-milling industry"? A. To contrast the organization of the grain trade with the organization of the flour-milling industry. B. To explain how the economic organization of the long-distance trade in grain differed from that of the local economy. C. To illustrate how the local flour-milling industry differed from the long-distance flour-milling industry. D. To argue that the flour-milling industry made the long-distance grain trade more dynamic than the local grain trade.