Step 1: Understanding the events
- (A) Boris Yeltsin became the head of the Communist Party in Moscow in 1990, a crucial event as he would later play a significant role in the dissolution of the Soviet Union.
- (B) In 1990, the Soviet Union declared that Warsaw Pact members were free to decide their own future, signaling a shift towards independence for former Soviet allies.
- (C) In 1991, Boris Yeltsin became the President of Russia, a key moment in the disintegration of the Soviet Union, as the Russian Federation declared its independence.
- (D) The Commonwealth of Independent States (CIS) was established in December 1991 after the collapse of the Soviet Union, comprising 11 former Soviet republics.
Step 2: Arranging the events chronologically
- The correct chronological order of these events is:
1. (A) Boris Yeltsin is appointed as the head of the Communist Party in Moscow.
2. (B) Soviet Union declares that the Warsaw Pact members are free to decide their own future.
3. (C) Boris Yeltsin becomes the President of Russia.
4. (D) The Commonwealth of Independent States is established.
Step 3: Conclusion
The correct order is (A), (B), (C), (D), making option 1 the correct answer.