Respuesta :
The correct answer is A.
After decades of confrontation during the so-called Cold War that started after WWII, the URSS, that leaded the Eastern bloc of communist countries collapsed in 1991. The Union of soviet republics was dismantled and its largest member, Russia, and also the other former members started to transform their economies and to adopt market economies. Meanwhile, the US, the other global superpower that had leaded the Western bloc of capitalist countries during the Cold War, was left as the only global superpower.