Yugoslavia Became the Most Troubled of Former Eastern European Communist

Yugoslavia became the most troubled of former Eastern European communist countries because of all of the following EXCEPT

A) It was a multi-ethnic state created after World War One.
B) It became embroiled in a war with Czechoslovakia.
C) NATO forced its military occupation in the area.
D) Russia attempted to destroy any attempt at independence.
E) The area was a division of Muslims, Catholics, Jews, and Orthodox