Which country joined the UNO in 2006

Which country joined the UNO in 2006
A: Montenegro
B: Macedonia
C: Hong Kong
D: East Timor

Montenegro became an independent country in 2006 following its separation from the State Union of Serbia and Montenegro. Shortly after gaining independence; Montenegro applied for and was admitted to the United Nations on June 28; 2006. Its membership marked an important milestone in its recognition as a sovereign state on the global stage.