Answer:
The Domino Theory was based on the idea that communism was a contagious force that spread from country to country. It was first advanced during Harry S. Truman's presidency, when WW2 ended, as the United States adopted the policy of Containment to restrict communist expansion and the sphere of influence held by the USSR.
The policy established by Mikhail Gorbachev was called glasnost and it can best be described as the policy of open discussion of political and social issues, which resulted in changes to the Soviet political structure. The correct option among all the options that are given in the question is the second option.
B and C makes sense to me
Answer:
a change from a mainly agricultural to a mainly industrialized economy
