In which business did andrew carnegie create a monopoly?
the steel business
the oil business
the automobile business
the telephone business

The correct answer is:

the steel business  

Explanation:

A monopoly is defined by a lack of competition, which can mean higher costs and lower products. However, the great economic power that monopolies hold has also had positive outcomes for the U.S.Andrew Carnegie. The Scottish-born American financier and benefactor Andrew Carnegie (1835-1919) was one of the first "captains of industry." The leader of the American steel industry from 1873 to 1901, he influenced of his great fortune by providing educational, cultural, scientific, and technological institutions.

d and a is the correct anwsers

explanation:

b. florence

d. milan