How did John D. Rockefeller horizontally integrate his monopoly in 1880? A.)He purchased iron mines around the country to add to his business.
B.)He created a trust that controlled ninety percent of the nation's oil refineries.
C.)He created a trust that controlled oil wells, refineries, and distribution networks.
D.)He purchased coal plants around the country to add to his business.

A.) He purchased iron mines around the country to add to his business. He created a trust that controlled ninety percent of the nation's oil refineries. He created a trust that controlled oil wells, refineries, and distribution networks.

Explanation:

the first historical instance of china engaging in internationalism was during the han dynasty.[1] at the start of the han dynasty, the huns in the north were attacking the frontiers of han and trying to obtain riches. emperor wu of han wanted to gain an alliance with a country called dayuezhi so the two countries could join together and fight against the huns.[2] to obtain this alliance, emperor wu sent zhang qian to the west to establish economic and cultural connections.[2] history records that during the han dynasty there were four primary avenues of contact between china and europe. they included the northern land route, the central land route, the southern sea route, and the far southern sea route.[1] the most famous of these routes is the central land route, or the classical silk road, comprising a network of roads stretching from northwest china to the ports of syria and the black sea, which passed through the oasis of the turkestans and northern persia.[1] the silk road was significant for chinese emperors because it provided dominance over central asia by developing resources and provided new markets for the export of china's most valuable resources.[1]