Answer:
B. The spread of communism throughout the world
Explanation:
The Soviet Union saw itself as the nation that represented communism in the world, and for this reason, it promoted the spread of this economic system through all possible means: diplomacy, investment, and even war.
The Soviet Union did not only have an ideological interest in spreading communism, but also a geopolitical interest: it was embroiled in a Cold War with the United States, at the time, the other superpower of the world, and the U.S. was the adversary because it had another economic system: capitalism, which is opposite to communism in economic terms.