Which factors were most responsible for the economic development of the north during the early to mid-1800s?
a. large forests, abundant cash crops, and mineral resources
b. vast stretches of land, rich plant life, and humid climate
c. fertile soil, frequent rainfall, and warm temperatures
d. safe harbors, cool weather, and rocky soil

Option A is the right answer.

Explanation:

Many Europeans immigrated to northern states as there was a boom in the economy due to rapid industrialization. They were semi-skilled apprentices and they mostly looked out for factory and railroad jobs. Due to large sized immigrations, the cities in the northern states were filled with quality and cheap labor which was an added advantage.

Demand for the products was highest as it was machine made goods and not man made products. Farmers were not given loans as they were unable to pay and bankers could not reap profits. Demand for the consumer durables was highest.  

Large supply of cost effective and economical labor, effective conveyance of goods and demand for the products were the advantages of northern states’ economy to rise.

a.that is my answer.

brainliest .