Contrast the social structure of the Middle Ages and the Renaissance.

d.prevent the spread of communism outside of eastern europe.

i believe the correct answer is option b. most eastern european nations joined nato.

though i could be wrong, option d. the eastern european nations were granted complete independence, would be another choice.

hope this ! : )

answer; (b) asia;

the united states broke it's neutrality was the constant german sinking of trading vessels resulting in the loss of lives, one example would be the lusitania.