The greatest challenge cities faced as a result of rapid industrialization in the 1800s was providing enough city services to protect and support new citizens. Option D is correct.
As a result of rapid industrialization in the 1800s there was a dramatic increase in the number of the people from rural areas moving into the cities to find a better life where industries where located. Machines replaced hand labour as the main means of manufacturing, increasing the production capacity of industry tremendously.
