What was the overall impact of perestroika and glasnost on the Cold War?

AThey strengthened the communist system in Eastern Europe.
BThey brought an end to the strategic arms race between the United

States and Soviet Union.

CThey helped lead to the collapse of communist regimes in Eastern

Europe.

DThey led to the SALT I and II agreements.
EThey resulted in the Iran-Contra Aff air.