The correct answer is (d), Monaco.
Monaco has a population of 38,745, according to the United Nations Statistics 2012. The other options are:
- Marshall Islands: 53,158
- Dominica: 72,394
- St. Kitts and Nevis: 53,289
Monaco is a small principality located on the Mediterranean Sea. It is the second smallest country in the world by area, after Vatican City. Monaco is a popular tourist destination, known for its casinos, luxury hotels, and beautiful scenery.
