(A) The Ottoman Empire
(B) ** The Soviet Union
(C) Germany
(D) Austria-Hungary
EXPLANATIONS BELOW
Concept note-1: -The Central Powers’ origin was the alliance of Germany and Austria-Hungary in 1879. Despite having nominally joined the Triple Alliance before, Italy did not take part in World War I on the side of the Central Powers. The Ottoman Empire and Bulgaria did not join until after World War I had begun.
Concept note-2: -The Central Powers were Germany, Austria-Hungary, and Turkey, while the Allies including France, Britain and its domain, Russia, Italy, Japan, and from 1917, the United States of America.
Concept note-3: -The Allies described the wartime military alliance of Germany, Austria-Hungary, Bulgaria and the Ottoman Empire as the ‘Central Powers’.
Concept note-4: -World War I was fought between the Central Powers comprising Germany, Austria-Hungary, Bulgaria, the Ottoman Empire; and the Allied Powers comprising Great Britain, France, Russia, Italy, and Romania.