Final answer:
The challenges to the authority of the daimyo in Japan included the dismantling of the feudal system, restrictions on their alliances, and taxation of their stipends.
Step-by-step explanation:
The daimyo in Japan faced several challenges to their authority during this period. One major challenge was the dismantling of the feudal system by the Tokugawa government, which forced the daimyo to give up their domains and redistributed the land into prefectures. Although the daimyo were allowed to remain as rulers of the prefectures, they had to spend every other year in Edo (modern-day Tokyo) to ensure their loyalty to the shogun. Additionally, the daimyo's stipends were made subject to taxation and distributed in the form of government bonds, which further diminished their power.