It wouldn't be C or B the closest answer I would say is A because Stalin didn't want the other democratic states to join against him. During that time it was also the cold war.
a. Soviet leaders wanted to maintain a buffer between Russia and the West, fearing intervention by capitalist countries.
Explanation:
The fear of encroachment or an invasion has always been important in Russian strategic thought, no matter what regime is in power. Terrible historical experiences like the Napoleonic invasion of 1812 and the Nazi invasion of 1941, have always been present in the minds of Russian rulers. You might even go further, to the times of Mongol conquest of Russia. For secretary-general Joseph Stalin, the Soviet military presence in Eastern Europe provided an opportunity to expand communism and increase Soviet influence. Surrounding itself with satellite states not only increased communist reach, it also gave the USSR a buffer zone that improved its security.
