Questions Refer to the Passage Below

Questions refer to the passage below.
"Eight to ten million soldiers will swallow each other up and in so doing eat all Europe more bare than any swarm of locusts. The devastation of the Thirty Years War compressed into the space of three or four years and extending over a whole continent; famine, sickness, want, brutalizing the army and the mass of the population; irrevocable confusion of our artificial structure of trade, industry and credit, ending in general bankruptcy; collapse of the old states and their traditional states craft, so that crowns will roll by dozens in the gutter and no one will be found to pick them up; it is absolutely impossible to predict where it will all end and who will emerge from the struggle as victor. Only one result is absolutely certain: a general exhaustion and the establishment of the conditions for the final victory of the working class."
Friederich Engels, German Socialist, 1887 from James Joll, The Origins of the
First World War, New York: Addison Wesley Longman, 1992
-Of the following events, which one MOST closely resembles what Engels believed to be "absolutely certain"?

A) The Russian Revolution
B) The rise of fascism in Italy and Germany
C) The Great Depression
D) The rise of anticolonial movements