After collecting the data - from citypopulation + wikipedia - I would say that "Urban Area" should be better specified to "Metro-Area", as all of the cities quoted in my previous comment reach 1M inhabitants only by considering the full Metro Area.
Good idea helps with getting a better grasp on where some of these cities are. Took me 3 tries to get full score, but I am tempted to continue playing until I have the locations of these places with certainty. (But since I said to myself, this is the last quiz for now like almost an hour and many quizzes ago, it will have wait until another time)
At least give your source!