Final answer:
The correct answer to the question is B. The White armies in the Russian Civil War failed to develop unified political plans or adequately coordinate their efforts, leading to their defeat by the Bolshevik-led Red Army, which eventually led to the establishment of the Soviet Union. The correct answer is option B.
Step-by-step explanation:
During the Russian Civil War, B. the White armies almost captured the country, but proved unable to develop unified political plans or adequately coordinate military activities. The Whites were a disparate group, including former Tsarists, various political factions, and ethnic minorities who wanted independence, such as Ukrainians labeled as Kulaks. Despite support from foreign powers like the United States, Britain, France, and Japan, their internal disunity and lack of a coherent political vision failed to overthrow the Bolsheviks, led by Vladimir Lenin.
After the execution of Tsar Nicholas II and his family, the Red Army, organized by Leon Trotsky, fought against these disparate forces. The Red Army was more unified and better organized, with a clear objective to establish a communist government. Despite the foreign intervention, including American troops supporting the White Army, the Red Army prevailed by 1921, leading to the formation of the Soviet Union in the early 1920s.