Internal economies in the U.S. during its period of industrialization

Internal economies in the U.S. during its period of industrialization involved the

(a) production of goods in factories.
(b) production in small, isolated towns spread throughout the U.S.
(c) production of goods in factories grouped together in the same geographical region.
(d) production of goods in isolated factories spread throughout the U.S.

ANSWER

(a)