Select the sentence with consistent verb tense.
Cities like Pontevedra in Spain will experiment with banned cars, which had made streets safer and more pleasant.
Cities like Pontevedra in Spain are going to experimenting with a ban on cars, and made streets safer and more pleasant.
Cities like Pontevedra in Spain are experimenting with banning cars, making streets safer and more pleasant.
Cities like Pontevedra in Spain are experimenting with banned cars, which will have made streets safer and more pleasant.