The correct option is D Glasnost, Perestroika
Mikhail Gorbachev who assumed power in the USSR wanted to bring about changes in the USSR administration and introduced liberal policies like Glasnost and Perestroika in 1987. But these policies diluted the power of the Communist Party in the USSR. The USSR weakened and disintegrated into 15 new states, and what we recognise as Russia today is one among them.