The correct option is D Ideologies like Socialism and communism flourished.
The immediate effects of the First World War was increase in poverty and hunger, and worsening conditions of the working class across Europe. Ideologies like Socialism and communism flourished. The working class people naturally began to incline towards socialism and communism. The Bolshevik government, under the leadership of Vladimir Lenin, signed a peace treaty with their war opponents, the Central powers, in 1918, to stay away from the war.