B) Preventing the spread of communism
The role of the united state in Vietnam war began after the world warII. US mission was to restrict the communist domination that was present in Vietnam government, this was because communism could easily spread to the Neighbouring countries which would result to a change in the balance of power throughout Southeast Asia.
The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
The Bolshevik Revolution brought about Lenin's "April Theses" blueprint to some extent because it was the document in which Vladimir Lenin expressed his ideas and philosophy for Russia. Lenin (1870-1924) came up with ten interesting points where he referred to the revolutionary ideal in a time of change for Russia. He unveiled the content of "April Theses" in 1917, before the attendants to the April Bolshevik Conference.
These ideas supported changes in the Tsar's government system and urged the Social Democratic Labor Party of Russia to consider rebellion as an option.
Jim Crow laws mandated racial segregation in all public facilities in the states of the former Confederate States of America and in some others, beginning in the 1870s.
They restricted public use of "white only" Resturants, water fountains, theatres and bathrooms. Many more.