Large increases in the need for food led the Han Chinese government to encourage more intensive farming in the fragile
environment of the Huangtu Plateau. At the same time, new iron refining techniques produced better plows and other farm tools.
Iron smelting technology involved purifying and hardening iron in various kinds of furnaces.
What environment-damaging activity was partly caused by iron smelting?
A.
desertification
B.
terracing
C. deforestation
D. overgrazing