(A) Germany
(B) Italy
(C) ** Austria-Hungary
(D) Serbia
EXPLANATIONS BELOW
Concept note-1: -Franz Ferdinand was the eldest son of the archduke Charles Louis, who was the brother of the emperor Franz Joseph. The death of the heir apparent, Archduke Rudolf, in 1889 made Franz Ferdinand next in succession to the Austro-Hungarian throne after his father, who died in 1896.
Concept note-2: -Archduke Franz Ferdinand Carl Ludwig Joseph Maria of Austria was the heir presumptive to the throne of Austria-Hungary. His assassination in Sarajevo is considered the most immediate cause of World War I.
Concept note-3: -Franz Ferdinand was the eldest son of Archduke Karl Ludwig of Austria, the younger brother of Emperor Franz Joseph I of Austria. Following the death of Crown Prince Rudolf in 1889 and the death of Karl Ludwig in 1896, Franz Ferdinand became the heir presumptive to the Austro-Hungarian throne.
Concept note-4: -Just hours after narrowly escaping an assassin’s bomb, Archduke Franz Ferdinand, the heir to Austro-Hungarian throne and his wife, the Duchess of Hohenberg, are killed by Gavrilo Princip.