Answer:
Correct answer is C. The resignation of Mikhail Gorbachev
Step-by-step explanation:
Option A is not correct as this treaties are important for the limitation of weapon arsenal, but didn't lead to end of Cold War.
B is not correct as the defeat of US in this war showed that Communism is still alive.
C is correct as after his removal Soviet Union was dissolved, which led to end of Cold war.
D is not correct as China was opened towards the west even during the Cold war.