How did the economy of China change during the Zhou Empire?

China’s economy expanded as farmers using iron tools were able to grow more food.

China’s economy contracted as nomads from the north raided villages and threatened cities.

China’s economy was threatened by Huang River floods, resulting in widespread famine.

China’s economy stalled as battles among warlords disrupted planting and destroyed crops.

China’s economy was bolstered by the introduction of a unified currency and the development of a merchant class.