Which of the following was a reaction to the expansion of communism into eastern europe?
a. withdrawal from the vietnam war
b. formation of nato as a defensive alliance
c. the new deal

B. Formation of NATO as a defensive alliance

Explanation:

After World War II, as the Cold War began, the Soviet Union had shown that it wanted to expand its area of control in Eastern Europe.  In response, the United States, along with Canada, joined with ten European countries in signing the North Atlantic Treaty in 1949.  This created the North Atlantic Treaty Organization (NATO), which was a defensive military alliance of democratic states over against the expanding threat of communism felt in the Cold War environment.  The ten original Western European members of NATO were the United Kingdom, France, Belgium, the Netherlands, Denmark, Norway, Portugal, Italy, Iceland, and Luxembourg.

Following the formation of NATO, the Communist bloc, led by the Soviet Union, responded.  The Warsaw Pact was created as an alliance of Europe's Communist nations.  The Warsaw Pact was given that name because the agreement was signed in Warsaw, Poland.  Established in 1955, the Warsaw Pact included the Soviet Union, Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, and Romania.  The nations signing the treaty called on each other to defend of any member of the Pact that was threatened by enemy forces.  

it was the first amendment