The correct answer is C) The Balkans.
Archduke Franz Ferdinand supported Austria-Hungary’s growth and dominance in the Balkans region.
Franz Ferdinand made possible the growth of the Austria-Hungary empire to control the region of the Balkans. But on June 28, 1914, during a visit to Bosnia, he and his wife were assassinated by a Serbian nationalist. For this reason, Austria-Hungary declared the war on Serbia. On the next days, Germany declared war on Russia, invaded France, and this provoked Great Britain which declared war on Germany.