The correct answer is D, as the War of 1812 had a profound impact on the American economy by causing an increase in manufacturing.
Great Britain was the main producer of manufactured goods of that time. The United States satisfied its demand by importing British products, but as a consequence of the war, and of the obvious cessation of imports of British products, the American government began to encourage the national production of industrial goods, which generated an increase in national industrial production.
This war opened the doors to the industrial revolution in the United States.