Question

Which business practice did Rockefeller repeatedly use that helped him succeed in building his oil monopoly?
In all his businesses, Rockefeller made a profit and used it to expand or buy other businesses.
With every business Rockefeller bought, he would learn about it, sell it at a profit, and buy another business.
With every purchase of a refinery, Rockefeller would add new products to his business.
In all his businesses, Rockefeller made sure that he controlled all aspects of production.

Answer 1

In all his businesses, Rockefeller made sure that he controlled all aspects of production.

Explanation: Rockefeller practiced vertical integration — owning and controlling oil wells, refineries, pipelines, tank cars, storage, and distribution — which lowered costs, raised barriers to entry, and let Standard Oil dominate the market.