How did rome build its economy without the existence of an extensive trade industry? youra) roman leaders led extensive military expeditions to conquer foreign territories and increase access to trade routes. b) all other city-states were forced to pay taxes to the roman catholic church in rome. c) roman leaders encouraged a revival of the arts, and paintings and writings were sold to build up the economy. d) because the roman catholic church was the center of the city-state, church officials raised money for the city.