Read these headlines and answer "Warsaw Pact Tanks Invade Budapest" "Wall Divides Berlin" "Liberal Czechoslovak Government Replaced" . These 3 historical newspaper headlines above were related to :

1) Mikhail Gorbachev's introduction of the policy of glasnost

2) Adolf Hitler's efforts to promote national socialism

3) the Soviet Union's acceptance of capitalism

4) attempts by the Soviet Union to strengthen Communist control ​