Never.
No , not yet
bosnia was once part of yugoslavia. yugoslavia had a socialist government. in the early to mid 1990's their was a violent civil war which led to yugoslavia dividing into five countries; Slovenia, Croatia, Serbia, Macedonia, and Bosnia and Herzegovina. so yes bosnia was once part of the socialist union of yugoslavia.
Yugoslavia does not exist. Croatia was part of that country.
Yes, as part of the now dissolved Republic of Yugoslavia, from 1945 to 1992.
Bosnia and Herzegovina and Croatia were formerly part of Yugoslavia (full name Socialist Federal Republic of Yugoslavia) until declaring independence in 1992.
No.
Full name of Macedonia is Former Yugoslav Republic of Macedonia, so Macedonia was a part of Yugoslavia. Slovenia was also a part of Yugoslavia. Slovakia however was not a part of Yugoslavia, but it was a part of Czechoslovakia, both of them were communist countries after WW2.
it was part of socialist Yugoslavia, so yes
nope
never was a part
Europe