Which modern country was not part of Yugoslavia?

Albania was not part of Yugoslavia. Albania is a Balkan country in Europe bordered by North Macedonia to the west, Montenegro to the northwest, Greece to the southeast, the disputed territory of Kosovo to the northeast and the Adriatic Sea to the west. Yugoslavia was a socialist republic that existed between 1918-1992 which was formed from some of the former territories of the Austro-Hungarian Empire.

It first served as a monarchy after the end of World War I from 1918-1941, and as a socialist republic during the Cold War until it finally collapsed in 1992. In the latter years of Yugoslavia's existence, it suffered from ethnic and religious differences which resulted in a conflict known as the Yugoslav Wars which saw the independence of the former republics. It consisted of the modern countries of Serbia, Bosnia and Herzegovina, North Macedonia, Slovenia, Croatia, and Montenegro; as well as the disputed territory of Kosovo.