Final answer:
The doctrine of 'Socialism in one country' prioritized building a socialist state within the Soviet Union itself and was key in Stalin's consolidation of power, making option C the correct answer.
Step-by-step explanation:
The idea of "Socialism in one country" was a significant aspect of Joseph Stalin's rise to power in the Soviet Union. Contrary to the idea of promoting international socialism, this doctrine emphasized building and defending a socialist state within the Soviet Union first, before trying to spread the movement globally. This concept played an integral role in Stalin's consolidation of power as it focused on national development over international cooperation. The correct answer to the student’s question would be C. It prioritized socialism within a single nation. Stalin's plan involved a state-mobilized commitment to building Russian industry and agriculture, ultimately leading to a totalitarian regime where the state exerted control over many aspects of life to meet its objectives. By keeping the focus on internal development, Stalin was able to maintain control and justify his stringent measures.