During the entire period of 1820–1920, there were persistent trends

During the entire period of 1820–1920, there were persistent trends in the structure of American foreign trade. They exhibited

(a) a decrease in imported finished manufactures and an increase in exported finished manufactures.
(b) an increase in the exports of crude materials and foodstuffs and a decline in their importation.
(c) increases in both imports and exports of manufactured goods and foodstuffs.
(d) no exports or imports.

ANSWER

(a)