"The Crisis" written by Thomas Paine is a call to support the American cause.
I believe the answer is: A. <span>Austria-Hungary had taken over Bosnia and dominated Serbia.
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<span> in 1908, Austria-Hungary occupied some part of Bosnian empire which ignite economic crisis in Bosnia, which led to their fall. The austria-Hungary later than continue their advance toward serbian territory.
</span>Serbia had a very close relationship with Bosnia because they were once a part of the ottoman empire. So they decided to banded up together to oppose Austria-Hungary's forces.