(A) Slavs
(B) ISIS
(C) ** Bolsheviks
(D) Bulgarians
EXPLANATIONS BELOW
Concept note-1: -Tsar Nicholas II and his family are executed by the Bolsheviks in Yekaterinburg.
Concept note-2: -During the Russian Revolution, the Bolsheviks, led by leftist revolutionary Vladimir Lenin, seized power and destroyed the tradition of czarist rule. The Bolsheviks would later become the Communist Party of the Soviet Union.
Concept note-3: -Bolshevik, (Russian: “One of the Majority”), plural Bolsheviks, or Bolsheviki, member of a wing of the Russian Social-Democratic Workers’ Party, which, led by Vladimir Lenin, seized control of the government in Russia (October 1917) and became the dominant political power.
Concept note-4: -Economically, widespread inflation and food shortages in Russia contributed to the revolution. Militarily, inadequate supplies, logistics, and weaponry led to heavy losses that the Russians suffered during World War I; this further weakened Russia’s view of Nicholas II. They viewed him as weak and unfit to rule.