Which statement best explains how improved transportation technologies affected the economies of ancient civilizations?
A. Tax collectors could travel into distant provinces, making it possible for the governments to raise and spend large amounts of money.
B. Merchants could carry goods long distances, allowing these civilizations to specialize in producing certain items and gain wealth through trade.
C. Armies could supply troops in distant lands, making it easier to gain wealth through conquest.
D. Farmers could transport their crops to distant markets, allowing the civilizations to colonize large, distant territories.