Answer:
The purchase of Allegheny Steel helped Carnegie form a monopoly by giving him access to raw materials. Allegheny Steel was a major producer of iron ore, which was a key raw material in the production of steel. By acquiring Allegheny Steel, Carnegie was able to control a significant portion of the supply of iron ore, which gave him a major advantage over his competitors.
In addition to giving Carnegie access to raw materials, the purchase of Allegheny Steel also helped him to reduce his production costs. Allegheny Steel was a well-managed company with efficient production methods. By merging with Allegheny Steel, Carnegie was able to learn from their expertise and improve his own production methods. This helped him to reduce his costs and increase his profits.
The purchase of Allegheny Steel was a major step in Carnegie's journey to becoming a steel monopoly. By acquiring Allegheny Steel, Carnegie was able to gain control of a significant portion of the supply of iron ore and reduce his production costs. This gave him a major advantage over his competitors and helped him to achieve his goal of becoming the dominant player in the steel industry.
The other options are incorrect. The purchase of Allegheny Steel did not help Carnegie produce steel more efficiently, control most of the rail lines, or give him control of coke production.