During the Industrial Revolution in the 18th and 19th Century

During the Industrial Revolution in the 18th and 19th century, managers who could make minor improvements in management tactics were noteworthy. Why?

A) They brought robotics technology to mass production.
B) They subscribed to human relations theory.
C) They perfected quantitative management.
D) They developed the Hawthorne effect.
E) They produced impressive increases in production quantity and quality.