An investigation of the transition to democracy in Eastern Europe would most likely help to prove true the statement:
Religion could be practiced more freely in most Eastern European countries.
This reflects the changes that often occurred as countries transitioned away from Soviet influence, where religious practices were heavily restricted, towards more democratic governance, allowing for greater religious freedoms. The other statements are less accurate as they either overstate the dominance of the Soviet Union after the Cold War, oversimplify the challenges faced in adopting a free market, or mischaracterize the state of democracy across all former Eastern Bloc countries.