challenge: Which of the following statements about Rottumeroog is true?
  
  A. Rottumeroog is not part of the Netherlands.
  B. It is the most populated island in the Wadden Sea.
  C. The island is located between Rottumerplaat and Texel.
  D. Rottumeroog is one of the West Frisian Islands in Groningen.
  Answer: 