The primary reasons for the collapse of the Soviet Union are complex and multifaceted, but the most relevant option from your list is:
- The Soviet Union put all its resources on building the military.
This military focus contributed to economic stagnation, as significant resources were diverted away from consumer goods and infrastructure, leading to widespread dissatisfaction among the population.
While options 2 and 3 may have aspects worth considering, they are not as directly related to the primary causes of the collapse. The reduction of state control of the economy (option 3) was part of a reform process initiated by Mikhail Gorbachev, which had mixed results but is not generally considered a primary reason for the collapse itself.
Option 4, the focus on exporting natural resources, is also a factor but relates more to economic issues and dependency rather than a direct cause of the political collapse.
Overall, the excessive military spending combined with economic mismanagement, political reformation, and rising nationalistic movements contributed greatly to the eventual disintegration of the Soviet Union.