The person Cvjetko Popović was involved in the assassination of became heir presumptive to the Austro-Hungarian throne in what year?
Cvjetko Popović: Cvjetko Popović (Serbian Cyrillic: Цвјетко Поповић; 1896 – 9 June 1980) was a Bosnian Serb who was involved in the 1914 assassination of Archduke Franz Ferdinand of Austria.
i don't know