Answer:
The right choice is:
D. retained control of many countries in Eastern Europe and installed communist governments.
Explanation:
At Yalta, the leaders of the Three Big - USA, USSR, Great Britain - agreed on the future political division of Europe. Some historians and critics say that future spheres of influence were agreed on. In my opinion, it is correct, regardless of the formal language of the declaration adopted. The members of the coalition that would be occuping Germany and other countries´territory after the war would be given the right to have a decision on the order and the affairs of those countries under occupation. In practice, this gave the Soviet Union the possibility to station large numbers of troops in liberated Eastern countries and have a say on its political future.
Britain´s Winston Churchill insisted on holding free elections in the occupied nations, and all of them agreed, including Soviet leader Joseph Stalin. But after 1945, Soviet forces remained in Eastern Europe and helped local communist movements to win elections. So, the Soviet Union installed communist governments in that part of Europe and formed a political and military bloc with them.