Question

50PTS! How did the annexation of Bosnia and Herzegovina in 1908 intensify the rivalry between Austria-Hungary and Serbia?

Austria-Hungary vowed to take back the annexed territory from Serbia.
Serbia vowed to take back the annexed territory from Austria-Hungary.
Austria-Hungary attacked Serbia to stop ethnic unrest.
Serbia vowed revenge and recruited Russia to attack Austria-Hungary.

Answer 1

I think it is C. Austria-Hungary attacked Serbia to stop ethnic unrest.

Hope this helps!