Answer:
It was due to the factories and transport links being developed in urban centers.
Step-by-step explanation:
Urban centers grew primarily because the factories that were manufacturing machines created during the Industrial Revolution were built in urban areas. People wanted to work there so they moved to the urban centers. Factories were built in urban areas because the workers, the best transport links and the flattest land could be found there. With the development of agricultural technology, there was less manual labor needed on the farms so people migrated to the urban centers for work. Also, with the development of transport links, such as steam trains, people were willing to move further from home.