They could both serve as soldiers. :)
I think it is A B and C, but I am not completely sure, it might be B, C, and D.
Answer:
Standard Oil became a horizontal integration monopoly because it owned ninety percent of US oil refineries. It became a monopoly because it bought almost all of the competitors so that it managed to control almost all oil production, processing, marketing, and transportation in the United States.
Answer:
i think the answer may be D
