Queen Beatrix is the queen regnant of the Kingdom of the Netherlands, which is made up of 4 nations. Which of the below is not part of the Kingdom?

Explanation

Beatrix (Beatrix Wilhelmina Armgard; born 31 January 1938) is the queen regnant of the Kingdom of the Netherlands comprising the Netherlands, Curaçao, Sint Maarten, and Aruba. In 1966, she married Claus von Amsberg, with whom she had three children: Prince Willem-Alexander (born 1967), Prince Friso (born 1968), and Prince Constantijn (born 1969). Both Indonesia and Suriname used to be Dutch colonies.