In which rung in the cyclical pattern of cities did the problems of industrialization become most obvious?

The problems of industrialization became most obvious in the second rung of the cyclical pattern of cities, often characterized by rapid urban growth and industrial expansion. During this phase, cities faced significant challenges such as overcrowding, inadequate housing, pollution, and strained infrastructure. The influx of workers seeking jobs in factories led to social issues, including poverty and poor living conditions, which highlighted the negative consequences of industrialization.