How did the Bessemer process contribute to the development of Carnegie’s monopoly?

How did the Bessemer process contribute to the development of Carnegie’s monopoly?

A. It allowed Carnegie to produce higher quality steel more quickly, which increased demand.
B. It made transportation of steel faster and more efficient, lowering Carnegie’s costs.
C. It allowed Carnegie to cut his cost of labor, increasing his profits.
D. It allowed Carnegie to replace coal as a fuel supply, cutting his costs.