Which of the following was the main legacy of World War I on western society? A
the enlightenment belief that reason would prevail
B
two decades of economic gains
с
a sense of disillusionment with pre-war institutions
D
a lasting peace

whats youre

answer is b.

  it is always the best policy to have good communication and good relations between individuals and, specially, between leaders of the countries. for this purpose, among others, there is a common place, the united nations, where the representants can present his and learn about the other country's policies.