After the fall of the Roman Empire, political organization became interestingly local, the need for protection became more acute, and overall
trade declined. This contributed to an economic system called manorialism
which is best described as

A. an economic system based on markets and free enterprise

B. a communal system in which the wealth of all was shared equally

C. large plantations owned by Lords who used mainly slave labor to grow one cash crop

D. self-sufficient agricultural estates with landlords who gave protection and other
advantages in return for a portion of the good produced