The correct answer is C) it increased.
After World War II, what happened to the population in cities and suburbs was that it increased.
When World War II was over and the Postdam Agreement was reached by the Allies, and the Parise Peace Conference of 1946 was signed, many United States troops that were stationed in different European fronts started to return to the US. This made the population in many cities to increase their numbers. Cities grew in numbers and new infrac¿structure had to be built.
