The correct answer is C) horizontal consolidation-driving/buying out all other oil companies and /or entrepreneurs and vertical consolidation- buying into all industries needed to minimize costs, maximize profits, and dominate the oil market.
John D. Rockefeller was able to monopolize the oil market due to horizontal consolidation-driving/buying out all other oil companies and /or entrepreneurs and vertical consolidation- buying into all industries needed to minimize costs, maximize profits, and dominate the oil market.
John D. Rockefeller was the owner of the Oil-Standard Company. This Company practically controlled all the oil industry from 1870 to 1911. He created a monopoly by buying almost all the other oil companies and he had a vertical consolidation acquiring transportation and warehousing companies in order to reduce costs to a minimum and maximizes profits. He controlled the production process of oil, shipment, transportation, and selling.