Question

The success of the Bolsheviks in Russia contributed to the post-World War I phenomenon in the United States known as

Answer 1

The success of the Bolsheviks in Russia contributed to the post-World War I phenomenon in the United States known as the red scare - a. 

The red scare was a "movement" or rather stream of thoughts which feared the consequences which would be brought upon the American society in the case when communism would prevail.