Ngo dinh diem is the person who won the elections that unified vietnam
I would say D because A and B are more of the people's concerns and C isn't as much of a challenge due to high population. D is a concern of city officials that is considered a public concern.
One cause of the unparalleled material abundance of the US in the 1950's was is a population increase of about 30 millions. Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.