What is subsistence agriculture, and why does it often result in poverty?

subsistence agriculture occurs when farmers grow food crops to feed themselves and their families

Subsistence agriculture is when the farmers grow and farm only enough to eat for themselves and their families, but they don't grow to sell only to feed them and thier families

Explanation:

it should be a. song dynasty’s civil service examination system created an administrative bureaucracy manned by the landed aristocracy.

because it took place after the war of 1812 had come to an end.