Answer:
The correct answer is D. The advantage the North had over the South as the Civil War started was that it had more factories and workers to produce weapons.
Explanation:
A clear advantage of the North over the South at the beginning of the Civil War was the greater capacity of industrial production that it had on its opponent.
In the North the great capitalist industry was growing, with a large concentration of salaried labor, in full takeoff and at the doors of the Second Industrial Revolution (to which the war contributed, with the new military technologies such as the battleships or the production of mass weaponry).
In contrast, the South remained anchored in an economic system based on agriculture and primary exploitation, unfavorable to industrial development. Therefore, its supply of weapons depended in large part on purchases from countries such as Great Britain.