During the Industrial Revolution, the workers that supplied labor in factories and mines were known as the urban working class. Option D is correct.
The Industrial Revolution was a period between the 18th and 19th century, during which predominantly agrarian, rural societies in Europe and America became industrial and urban.
The working conditions were terrible during that timeperiod in history since employers could set wages as low as they wanted because people were willing to do work as long as they got paid.