How did men like carnegie and rockefeller change the business world? explain how their business practices would be viewed today. (5 sentence minimum)

ExplanaJohn D. Rockefeller and Andrew Carnegie increased the size of their business by creating monopolies that concentrated all the market of their respective interests (oil in the case of Rockefeller, and steel in the case of Carnegie) by buying all the competence.

yup! you are correct it is b.

answer; andrew jackson approved nullification by signing it into law,and john calhoun opposed it saying it was unconstitutional;