Curitiba, Brazil, Has Shown Us That _______________

Curitiba, Brazil, has shown us that _______________

A) prohibition of all motorized vehicles within cities reduces pollution and saves energy
B) traffic flows smoothly once pedestrians and bicycles are eliminated
C) unregulated urban sprawl produces severe air pollution
D) an expanded bus system, affordable to all, can solve a large cityʹs traffic congestion
E) once roads are widened, traffic congestion decreases