HELP PLEASE. Which answer

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

How did great depression affect germany and the soviet union differently

What were three advantages the north had in the civil war? it was fighting most battles on home ground. it had a greater number of soldiers. it had more highly skilled military leaders. it had a stronger navy. it had a better network of railroads. pick three .