Answer:
Correct answer is B. The League of Nations .
Step-by-step explanation:
B is correct answer because creation of League of Nation should have prevented new conflicts. It was its main task. Still, it didn't managed to fulfill its task at the end.
A is not correct as problems of colonies were unsolved. People in colonies still faced oppression.
C is not correct because this produced non-satisfaction among the Germans, which led to the rise of Nazis.
D is not correct because this also provoked tensions, especially in Germany.