Answer:
Option "c"
Step-by-step explanation:
All of the times
1. Warsaw Pact: May 14, 1955
2. Berlin Wall: August 13, 1961
3. German reunification: 1990
4. Marshall Plan: April 3, 1948,
5. Soviet Union breaks up: December 26, 1991
oldest to most recent:
1948, 1955, 1961, 1990, 1991
