Final answer:
Postwar Canada became more flexible and open due to its embrace of multiculturalism, which respects and celebrates diversity.
Step-by-step explanation:
After World War II, Canada became a more flexible and open society largely due to its embrace of multiculturalism. Unlike other ideologies at the time, such as capitalism, isolationism, or authoritarianism, multiculturalism has been a defining characteristic of Canada's evolution postwar. The country is recognized for its celebration of diversity, with an approach that respects the rights of all people to maintain their individual identities while contributing to the broader Canadian society.