Answer:
The correct result of the post-World War I Red Scare in the U.S. was <em>the limiting of the number of people allowed to immigrate to the United States</em>.
Explanation:
One major element of the Red Scare of 1919-1920 was the hatred and fear of immigrants in the US. Despite the fact that the peak of immigration happened in the turning of the 19th to the 20th century it was only after the war it led to mass hysteria.
This mass hysteria happened because associated with the big number of immigrants in the country there was the fear of communism because of the recent October Revolution (1917) in Russia. Russian immigrants and any other immigrants (Italian, Japanese, Spanish, Slavic) were seen as threats to the country.
This Red Scare is sometimes called the First Red Scare as the US had another famous wave of fear of communism in the 1950s.
All other statements are wrong because they refer to events that happened before the First Red Scare, except the first statement that is wrong because the Palmer Raids found almost nothing during its time.
