The right answer is A. Laws placing limits on the numbers of immigrants from certain countries to the United States were passed.
The Red Scare of 1919, the fear of the spread of communism, anarchism and radical leftism, generated an anti-immigrant hysteria in the US. The political post-war scenario was constantly blaming the foreign-born for all the disorder in the country. As a result, politics to restrict immigration were passed. The immigration acts of 1921 and 1924 restricted the number of Europeans that could immigrate to the US and completely denied the entrance of East Asian immigrants.