Who were the bolsheviks and how did they run russia?

The Bolsheviks were a revolutionary socialist party within the Marxist Russian Democratic Labour Party. They called themselves revolutionary as they believed that revolution is a step necessary to achieve the change from capitalism to socialism. They came to power during the "October Revolution" of 1917, founding the Soviet system. The Bolsheviks eventually became the Communist Party of the Soviet Union.  Through leadership of the Communist Party they run Russia firmly.

the answer is definitley b!

d.)   when the us left nato after the end of the cold war and they had to evolve to focus on more humanitarian measures with the smaller budget