The correct answer is the growth of suburbs and urbanization.
The availability and affordability of cars completely changed the living patterns of American citizens. This is due to the fact that people now did not have to live close to their work. Before the car became a product that a majority of Americans could afford, many citizens lived very close to their working places (usually within walking distance). However, with the increased availability of cars, people could work in the city and then drive out to the suburbs where their were nice shopping plazas, homes, and other amenities.
