How was rockefeller able to build his monopoly across the oil industry?
a) he bought up oil refineries, cut costs, and reinvested his profits in other refineries.
b) he confined his business to ohio so he could buy all the refineries there.
c) he found newer and cheaper ways to refine oil, increasing his profits.
d) he began to sell kerosene as well as oil, expanding his market.

Rockefeller was able to build his monopoly across the oil industry since he bought up oil refineries, cut costs, and reinvested his profits in other refineries.

Rockefeller was an American oil industry business magnate, industrialist, as well as philanthropist. He is widely regarded to as the wealthiest American of all time, and the richest person in modern history.

Rockefeller's wealth sky rocketed as kerosene and gasoline grew in importance, and he turnt into the richest person in the country, controlling 90% of all oil in the United States at his peak.

This Question has 3 parts so I am going to answer then all right now.

1) He bought up oil refineries, cut costs, and reinvested his profits in other refineries.

2) To grow his corporation, Rockefeller designed a new type of company called a TRUST

3) A trust is a large company or combined businesses that together control a specific market

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.

because they can and they wanted to.