How did World War I act as a turning point in world history?

AIt created alliances that eventually formed the Cold War's Eastern and Western blocs.
BIt resulted in the end of imperialism by promoting national self-determination.
CIt limited political and economic rights for women by tying those rights to military service.
DIt left unresolved political issues in Germany that led to another world war.

Verified Answer :

DIt left unresolved political issues in Germany that led to another World War 
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I say its A.), because after the war ended, everyone started to get along and they started trading.