Which of the following was NOT one of the reasons why Andrew Carnegie

Which of the following was NOT one of the reasons why Andrew Carnegie made enormous profits in the steel industry?

A) He willingly sacrificed the quality of his product to gain the economies of scale.
B) He paid his workers low wages for long hours of work.
C) He vertically integrated the steel production industry.
D) He made heavy investments in new technologies of production.

ANSWER
A