The warrior classes in medieval Japan, known as the samurai, played a significant role in the country's economy. They were often granted land by the feudal lords in exchange for their military service and loyalty. The samurai would collect taxes from the farmers working on their land, ensuring a steady stream of income for themselves and the ruling class. Additionally, they often served as enforcers of law and order, protecting trade routes and preventing banditry, which contributed to the growth of commerce in medieval Japan. Therefore, the best description of the role of the warrior classes in medieval Japan's economy is that they were landowners who collected taxes and protected trade routes.
