They needed the fur to make clothes because it was cold in Oregon.
The most thoughtful answer is b
Answer:
Technological innovations increased agricultural yields.
Explanation:
The Chinese economy in the period 1200-1450 increased due to higher production of agricultural crops with the use of new technologies. In the period of song dynasty, an early growing rice cultivar was produced which can be grown multiple times in a year. Due to multiple harvest, food was available in large amount for the people so we can say that innovations increase the yield of crops.
