When did the USSR formally disintegrated into 15 republics?

Option A

Union of Soviet Socialist Republics (USSR), Rus. Soyuz Sovetskikh Sotsialisticheskikh Respublik, former republic. It was established in 1922 and dissolved in 1991. The Soviet Union was the first state to be based on Marxist socialism (see also Marxism; communism). Until 1989 the Communist party indirectly controlled all levels of government; the party's politburo effectively ruled the country, and its general secretary was the country's most powerful leader. Soviet industry was owned and managed by the state, and agricultural land was divided into state farms, collective farms, and small, privately held plots.

Politically the USSR was divided (from 1940 to 1991) into 15 constituent or union republics— Armenia , Azerbaijan , Belorussia (see Belarus ), Estonia , Georgia , Kazakhstan , Kirghizia (see Kyrgyzstan ), Latvia , Lithuania , Moldavia (see Moldova ), Russia , Tadzhikistan (see Tajikistan ), Turkmenistan , Ukraine , and Uzbekistan —ostensibly joined in a federal union, but until the final year or so of the USSR's existence the republics had little real power. Russia, officially the Russian Soviet Federal Socialist Republic (RSFSR), was only one of the constituent republics, but the terms  Russia,  the  USSR,  and the  Soviet Union  were often used interchangeably.