Since the change in U. S. immigration policy during the 1960s to encourage immigration of relatives of U. S. residents and people with desirable skills, where have a majority of immigrants originated from

Mexico and other Lat.in American countries

Explanation:

More than half of the immigrants have originated form the developing countries as they leave due to desperate social and the economic circumstances. The largest group is formed by the Poland, Pakistan and Sweden and Germany Lithuania and the Vietnam. The act was called as Hart-Celler

Answer:   [b]:   "cultural" .