Feelings of resentment toward those who were not native citizens rose during World War I. This was known as:

The correct answer is B. nativism.

Nativism refers to the political policy of promoting the interests of native inhabitants over those of immigrants. During World War I, there was a rise in feelings of resentment toward immigrants who were not native citizens, as many people believed that non-native individuals could pose a threat to national unity and security. This sentiment often led to discriminatory attitudes and actions against immigrant communities.