Which institution that went out of use in the Zhou dynasty was reinstated by legalism

Which reason best explains why certain areas of southwest asia have low population density? a. the semi-arid climate makes farming difficult because it produces very little rainfall.b. the moist climate limits job opportunities because it reduces oil production.c. the semi-arid climate produces heavy rainfall that contributes to devastating floods. d. the moist climate reduces agricultural production by causing water shortages.