D. Cities grew in size as previously used farmland was absorbed into urban areas. The shift described in the excerpt led to the growth of urban areas as more people moved from rural areas to work in professional, technical, and service occupations. This resulted in the conversion of farmland and rural areas into urbanized regions, which had significant impacts on the physical environment, such as the loss of agricultural land, increased urban sprawl, and associated issues with traffic congestion, air pollution, and other environmental concerns.