The correct answer is: "The automobile industry used the substance to power cars and trucks."
When two industries that represents different stages of a same production process have nearby locations, vertical integration takes place, as they both profit from having either their suppliers or buyers close by. Such situations allows to reduce costs and to increase profits.
Also, the establishment of one of the industries might actually foster the development of the other, such as in the case of oil extraction, that triggers the apperance of industries who use oil as power nearby, as it is the case of the automibile industry.
