After world war ii, the soviet union maintained control of many eastern european nations mainly because these nations were extensions of communist power can you explain why this is the answer?

How does the principle of federalism affect the u.s. government? a. it guarantees that the united states will always be a representative democracy b. it ensures that the state governments have greater authority that the federal government c. it creates both separate and overlapping powers for the federal and state governments d.it divides the federal and state governments into three branches