Explain the term “division of labor” as it related to freemen on a landlord’s manor.

Narrow specialization of tasks within a production process so that each worker can become a specialist in doing one thing, especially on an assembly line. In traditional industries (see sunset industries), division of labor is a major motive force for economic-growth. However, in the era of mass customization (which requires multiple skills and very short machine change-over time), division of labor has become much more flexible. Also called specialization of labor.

For the answer to the question above.
The best answer I can give is letter B.
During the civil war, there was also a competition in the global market on the supply of cotton so Europe sought other suppliers from India and Egypt and this is why the price is down after 1865