What Does the Term "Economies of Scale" Describe

What does the term "economies of scale" describe?

A) government efforts to develop the economy on solid investments and produce goods carefully without concern for cost
B) Edison's development of small parts that could be interchanged between machines manufactured in his labs
C) the ability of the economy to respond to changes in supply and demand from year to year without disturbing investor confidence
D) business enterprises that produced large quantities of product cheaply thanks to large workforces and machines
E) the sort of economy that capitalists feared would result from too much government regulation