During the industrial revolution, especially at the beginning, living conditions deteriorated significantly. The workers moved to the cities, but there were no prepared places for them to stay, and it resulted in slums, with bad sanitary and safety conditions.
The answer would be B since when a city is undergoing urbanization people are moving in and not leaving.
I think it's d but are you talking about the Great Depression
The answer is C since that would mean he created the trail.