The correct answer is option 2 - 1991. The Soviet Union, which was a communist state in Eurasia, disintegrated into 15 independent republics in the year 1991. This event marked the end of the Cold War era and the dissolution of the Soviet Union as a political entity. It was a result of various factors, including the economic and political struggles within the Soviet Union, the rise of nationalism among the different republics, and the weakening authority of the central government. The process began with the declaration of independence by the Baltic states (Estonia, Latvia, and Lithuania) in 1990 and culminated with the signing of the Belavezha Accords in December 1991, which led to the formation of the Commonwealth of Independent States (CIS) and the official dissolution of the Soviet Union.