Answer:
A. major increases in the immigrant population in the United States.
Step-by-step explanation:
The Immigration Act of 1965, also known as the Hart-Celler Act, abolished the national origins quota system that had restricted immigration from certain regions, especially Asia and Africa, since the 1920s. The new law established a preference system based on family reunification and skilled workers, and set a numerical limit of 170,000 visas per year for countries in the Eastern Hemisphere and 120,000 for the Western Hemisphere. The law also removed racial and ethnic barriers to naturalization. As a result, immigration from Asia, Africa, Latin America, and the Caribbean increased significantly in the following decades, changing the demographic and cultural composition of the United States.