In 1644 the Chinese capital at Beijing was captured by the rebel leader Li Zicheng and desperate Ming dynasty officials called Manchus for aid
I don't know what the "followings" are, but I can tell you that Tenement buildings had no interest in caring for the people who lived there. Tenement housing had its people share bathrooms, there were no lights(besides the window), and the rooms were small and cramped.
The Answer is A to defend polis
Answer: Popular sovereignty