The correct option is D Under the leadership of Yeltsin, USSR was completely disbanded.
Mikhail Gorbachev was a liberal who tried to transform the politics of the USSR by making it more open and bringing about radical changes. Hardline communists tried to remove Gorbachev in a failed coup in 1991, which was foiled by Boris Yeltsin. When Boris Yelstin won the Presidential elections he announced the disbanding of the USSR in 1991. With the collapse of the USSR, a new era began in world politics.