How did this act allow the US to be more "selective" in who they allowed to immigrate into the US?

At the basis of the Act was the continuation and codification of the National Origins Quota System. It revised the 1924 system to allow for national quotas at a rate of one-sixth of one percent of each nationality's population in the United States in 1920.

Explanation:

19th amendment granted women the right to vote. the 19th amendment guarantees all american women the right to vote.