Stone pillars telling of focus on people's well-being and Buddhism spreads, are the right answer.
The Kalinga War was a war waged by the emperor of the Mauryan Dynasty, Ashoka against the king of Kalinga Raja Anantha. It was an autonomous feudal kingdom which was inhabited on the east shore of Odisha. It was one of the most extended and most savage battles in the history of Ancient Indian. The bloodshed of the Kalinga war is supposed to have urged Ashoka to embrace Buddhism. It was only after this war that he denounced the conquest by force and announced victory by Dhamma. Due to this policy, Buddhism spread throughout India and the pillar inscribed by Ashoka focused on the well being of humans.
A-a belief in the strength of the economy although all of these are very vague answers this one makes the most sense because it crashed because everyone thought they had enough money and bought too much stuff they didn't need.