How did the assassination of Archduke Francis Ferdinand by a Serbian nationalist end peace in Europe?

Pick one

Germany declared war on Russia after France declared war on Germany.

Great Britain declared war on Germany after Germany invaded France.

Austria-Hungary declared war on Serbia, causing Russia to help Serbia.

Russia declared war on Germany, causing Serbia to help Russia.

1 answer

The correct choice is:

Austria-Hungary declared war on Serbia, causing Russia to help Serbia.

The assassination of Archduke Francis Ferdinand set off a chain reaction of alliances and mobilizations that ultimately led to the outbreak of World War I. Austria-Hungary's declaration of war on Serbia prompted Russia to mobilize in defense of Serbia, which then escalated into a larger conflict involving multiple nations.