The correct answer is B. The merit system. The founders of the Song dynasty established a series of policies based on Confucianism that sought the development of trade and the effectiveness of the bureaucracy. To achieve this, they established a system of meritocracy based on equal evidence for all candidates for public office, thus achieving an objective system in which the aspirant's skills prevailed and everyone had the opportunity to achieve a prominent public position. Through this method the Song dynasty managed to establish a prosperous government and with a bureaucracy of 20,000 people managed to govern more than 100 million people.