How did Andrew Carnegie use vertical integration to dominate the steel industry?

Carnegie also created a vertical combination, an idea first implemented by Gustavus Swift. He bought railroad companies and iron mines. If he owned the rails and the mines, he could reduce his costs and produce cheaper steel. ... All these tactics made the Carnegie Steel Company a multi-million dollar corporation.

Explanation:

d.) then bernice winced as marjorie tossed her own hair over her shoulders and began to twist it slowly into two long blond braids until in her cream-colored negligée she looked like a delicate painting of some saxon princess. fascinated, bernice watched the braids grow. heavy and luxurious they were, moving under the supple fingers like restive snakes—and to bernice remained this relic and the curling iron and a to-morrow full of eyes.

the answer is b "spewing black smoke", i took the test and got 100%   hope i