B- The harsh conditions imposed by the Treaty of Versailles and an economic depression
Explanation:
The treaty of Versailles left many countries extremely poor, and wanting more land that they didn't get. Many times when there is a problem in a country, everyone blames a group of people even if they did nothing, which is what happened with the Nazis blaming Jewish people for the economic depression. Hard times made people be more proud of their country, which then turned into nationalism.
