Which conclusion is most valid concerning the breakup of the austro Hungarian empire?

The breakup of the Austro-Hungarian Empire was primarily driven by rising nationalist movements among its diverse ethnic groups, which sought self-determination and autonomy. The empire's failure to effectively manage its internal divisions, combined with the pressures of World War I and the subsequent Treaty of Saint-Germain in 1919, ultimately led to its dissolution. This fragmentation resulted in the creation of several independent nation-states, reflecting the diverse identities within the former empire. Thus, the most valid conclusion is that nationalism and external pressures were key factors in the empire's collapse.