in which business did andrew carnegie create a monopoly?\no the oil business\no the automobile business\no…

in which business did andrew carnegie create a monopoly?\no the oil business\no the automobile business\no the telephone business\no the steel business
Answer
Brief Explanations:
Andrew Carnegie was a prominent figure in the steel - making industry in the United States. Through vertical integration and other business strategies, he built a large and powerful steel - related business empire, approaching a monopoly in the steel business. He was not associated with monopolizing the oil, automobile, or telephone businesses.
Answer:
the steel business