In the Austrian Empire, the groups which wanted to establish an autonomous state were B. Czechs and C. Hungarians.As you probably know, the entire name of the empire is Austro-Hungarian Empire, which means that included both of these countries (as well as what is now considered to be Czech Republic). So obviously those groups wanted to separate and create their own nations.
B, founded the Niagara Movement
The answer is the North Vietnamese took over the South Vietnam spreading communism Southward and this proved the domino theory (if one country come under the influence of communism, the surrounding countries would follow).