Pretty sure it is C because it it divisible by 3. If you divide 15 you get 5 and if you divide 6 you get 2.
The solidarity movement in Poland spoke out against communism, won, and established the first non-committal government in eastern Europe. The rest of the countries soon followed.
It was the internal reforms of Mikhail Gorbachev, the last Soviet leader that led to the end of the Cold War
