How did the Soviet Union come to dominate Eastern Europe after World War II?

Responses
A by keeping troops in the region and setting up communist governmentsby keeping troops in the region and setting up communist governments
B by supporting communist parties in democratic electionsby supporting communist parties in democratic elections
C by agreeing with the United States to divide Europe in halfby agreeing with the United States to divide Europe in half
D by making a separate peace agreement with Germany

by making a separate peace agreement with Germany