A、Rapid population growth. B、Corrupt city government. C、Real estate speculators. D、Lack of immigration quotas. B恶劣的生存状态要归因于腐败的城市

(20) The living conditions for the poor and for immigrants in New York City during the late nineteenth century were truly wretched. Over one and a half million poor people lived in tenements, a form of barracks-like building that could house some five hundred people in a structure lacking heat and plumbing. The resulting poverty, disease, and crime made tenement life degrading and often fatal.
But almost as shocking as the city-conditioned horror of the tenements was the government’s neglect of normal city functions. (21) Real estate development was uncontrolled, resulting in factories, stores, and residents springing up randomly without consideration to zoning or building codes.
Pollution of waterways was unrestricted, streets were poorly paved, lighting was inadequate, and sewage disposal was insufficient. (22) But most of the wretched living conditions in the city must be attributed to the corrupt city government of the late nineteenth century.
Questions 20 to 22 are based on the passage you’ve just heard.
20 Who suffered most from poor housing conditions in New York City?
21. Why were factories, stores, and residents built with little consideration for zoning or building codes?
22. Who or what was responsible for most of these living conditions?