The correct answer is A) John D. Rockefeller.
John D. Rockefeller specialized in controlling all aspects of production, from the bottom to the top.
He was the owner of the Standard Oil company. In 1882, he was the owner of most of the oil companies in the United States. He indeed had the monopoly of petroleum in America. He had the knack of being a great business mind and he specialized in controlling all aspects of production, from the bottom to the top. So he bought the companies that were part of all of the line of extraction and production of the oil business, so all the money could stay in his companies. His business practices led to the antitrust laws in the United States.