let's look at all the options: The assassination of Archduke Franz Ferdinand angered Austria. -this is correct! This assassination happened in Sarajevo.
Serbia declared war on Austria,which caused Austria’s allies to go to war This is false: the opposite is true; Austria declared war on Serbia, and then Serbia's Ally, Russia joined the war
Nationalism increased tensions in the Balkan peninsula. This is true. Because of this a conflict could be foreseen.
Russia's mobilization plan called for an invasion of France through Belgium. This is false- not Russia, but Germany had such a plan.
Alliances caused a chain of events that pulled each country into war. Very true!
The two alliences were Austria-Germany-Italy and Russia-France-UK hope it helps
