Answer:
Manhattan Island is D.
The most highly populated island in North America. On only 59 square kilometers there's over 1.6 million people, which is not really odd considering that it's a big corporate and tourist hub and every day millions of people go through it. It's a place for business as well with all the famous skyscrapes like the Empire state building being there.
Hope this helped!
-RosemaryAndStars
