(A) 1, 3, 2
(B) 2, 1, 3
(C) ** 3, 1, 2
(D) 3, 2, 1
EXPLANATIONS BELOW
Concept note-1: -World War I started in 1914. In 1915, Italy entered the war. The USA entered the war in 1917. After the end of World War I in 1918, the Treaty of Versailles was signed in 1919.
Concept note-2: -World War I began after the assassination of Austrian archduke Franz Ferdinand by South Slav nationalist Gavrilo Princip on June 28, 1914.
Concept note-3: -This increase in militarism helped push the countries involved into war. The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary.