Question

which event preceded the revolutions of 1989?
solidarity candidates were elected in poland.
hungary implemented a free market economy.
communist rule ended in czechoslovakia.
gorbachev made reforms in the soviet union.

Explanation:

Gorbachev's reforms in the Soviet Union, such as perestroika and glasnost, created an atmosphere that influenced the political changes in Eastern - Europe leading up to the 1989 revolutions. The other events listed occurred either during or after the start of the 1989 revolutionary wave.

Answer:

Gorbachev made reforms in the Soviet Union.