John D. Rockefeller vertically integrate his monopoly in 1882 as D. He purchased iron mines around the country to add to his business.
It should be noted that monopoly simply means a market structure that is characterized by a single seller of a good.
In this case, John D. Rockefeller vertically integrate his monopoly in 1882 as he purchased iron mines around the country to add to his business.
Learn more about monopoly on:
brainly.com/question/13113415
#SPJ1