It was primarily the "b. formation of the Vietcong in Vietnam" that led the Truman administration to expand the containment doctrine to include Asia, since this was seen as a threat to democratic principles in the west as well.
Answer:
The statement is true, but applies for small countries were things are not far apart like England, the Netherlands, Belgium, and Germany.
In the United States, before the massification of cars, most people who worked in the city still lived in the cities because distances are much higher.
Only with the advent of cars and the construction of large highways within the cities, and between the cities, suburbanization was possible.
