Which of the Following Was Not One of the Ways

Which of the following was not one of the ways that Andrew Carnegie revolutionized the steel industry?

A) incorporating the Bessemer process in his steel manufacturing factories.
B) standardizing workplace procedures to achieve greater efficiency.
C) utilizing vertical integration to minimize costs and maximize profits.
D) restructuring the criteria for wages so that his workers could have the highest wage scales in the country.
E) applying rigorous cost accounting.