Answer:
d. multiculturalism.
Explanation:
The concept of multiculturalism refers to the coexistence of different cultures that include race, religion, ethnicity, etc and their acknowledgment within a dominant culture. The population of America was constituted of different ethnic groups who have migrated to America but their movement for recognition started particularly in the 1960s when Americans of African descent brought their fight for legal and political rights at the national stage in the civil disobedience movement.