The correct answer is "A".
The Domino Theory was developed in 1950 in the US administration. It proposed the idea that if one country in a region was governed by a left-wing power which shared communist beliefs, neighbor countries will follow suit. This led the United States to get involved in numerous armed conflicts around the world, such as the Korean War, in order to prevent the spread of Communism.
I believe its B as 'progressive' means <span>favoring or advocating </span>progress, change, improvement, or reform, as opposed to wishing to maintain things as they are, especially in political matters:<span>
</span>
<span>Thomas Paine wanted people to think about what was happening. He explained that the people must fight against the unfair and unjust ways of King George III and the British Parliament.
Hope this helped! If you have any questions I'm available.
</span>
The Greensboro sit-ins were protest in integrating lunch counters at Woolworths
