Select the correct answer.
Which event started World War I?
A.
the sinking of the Lusitania by German U-boats
B.
the assassination of Archduke Franz Ferdinand and his wife, Sophie
C.
Germany’s annexation of Alsace and Lorraine after the Franco-Prussian War
D.
the Russian enforcement of Pan-Slavism throughout Slavic nations
E.
the signing of treaties in 1839 and 1867 to protect Belgium’s neutrality