What significant challenge did cities face as a result of rapid industrialization in the 1800s?

There were many challenges that cities faced as a result of rapid industrialization in the 1800s. With industrialization came the establishment of factories and industries in cities. These led to high levels of pollution and to a reduction in the space that was meant to house residents. Moreover, as people moved to cities to work in these industries, the cities became overpopulated, and the number of poor or unemployed people grew.

i believe the correct answer is b.