What major invention significantly affected where urban centers concentrated? a. Electricity allowed factories to run 24 hours a day, in 12-hour shifts, making it necessary for factories to be as close to power plants as possible b. Improved textile machines meant that fewer people were required to run textile factories, so they could move to the countryside and employ a rural workforce c. The steam engine made it possible to transport goods without depending on waterways and allowed factories to be built away from the coasts, rivers, and canals