Which of the following regions became the main arena of conflict between the superpowers- the USA and USSR in the Cold War?

Europe

The correct answer is Option 3 - Europe

International alliances during the Cold War era were determined by the requirements of the superpowers and the calculations of the smaller states. Europe became the main arena of conflict between the superpowers. In some cases, the superpowers used their military power to bring countries into their respective alliances.