The correct answer is D. Bolshevik protesters organize a mass strike calling for the end of the czarist system.
Step-by-step explanation:
The Russian Revolution took place in 1917 as the monarchy system and specifically the czarist system ended in this country and the Soviet Union was created. This revolution first started with massive protests and strikes in the nation led by the Bolsheviks who requested the end of the czarist system, and the participation of Russia in the war. At the same time, groups wanted social changes that benefited the general population as Russia was experiencing massive food shortages. These protests were supported by many including military forces and due to this Czar Nicholas II abandoned the power, while Lenin ((leader of the BolSheviks) became the ruler in Russia.
According to this, option D is the one that correctly completes the diagram because the strikes led by the Bolsheviks were one of the first steps in the revolution and this occurred before military opposed the orders of government and before Czar Nicholas II lefts the power.