The correct answer is A. 1991.
The Soviet Union (USSR) was a political and economic union of 15 socialist republics that existed from 1922 to 1991. The USSR was the world’s first and largest communist state, and its collapse was one of the most significant events of the 20th century.
The USSR began to disintegrate in the late 1980s, as the country’s economy faltered and its people began to demand more freedom. In 1990, the Soviet Union’s first and only democratically elected president, Mikhail Gorbachev, came to power. Gorbachev introduced a series of reforms known as glasnost (openness) and perestroika (restructuring), which led to greater freedom of speech and political participation in the USSR.
In 1991, the Soviet Union’s 15 republics declared their independence. On December 25, 1991, Gorbachev resigned as president of the USSR, and the country ceased to exist.
Option B is incorrect because the USSR formally disintegrated in 1991, not 1992.
Option C is incorrect because the USSR formally disintegrated in 1991, not 1993.
Option D is incorrect because the USSR formally disintegrated in 1991, not 1994.