The correct answer would be, "The growing feudal system prevented internal political conflict and stopped northern invaders from threatening China." The Zhou Dynasty began alongside the rise of the Iron Age, this immediately increased the power of the Zhou military.
The daimyos were a class of nobles who owned large estates in Japan. Shogun Tokugawa Ieyasu set up a system called sankin-kotai in which he required all daimyos to spend every other year in Edo serving the shogun. What was a result of the sankin-kotai system?
