J.A. Hobson provided an economic critique of imperialism, Lenin expanded this into a theory of capitalist expansion, and Gandhi offered a moral and political critique based on non-violence and self-determination. All three are seminal figures in the intellectual history of anti-imperialist thought.

Russia Day, celebrated on June 12, commemorates the adoption of the Declaration of State Sovereignty of the Russian Soviet Federative Socialist Republic on June 12, 1990. While the provided answer key selects June 25, 1990, historical records confirm the declaration occurred on June 12. This day is a national holiday in Russia, marking the beginning of the country's transition toward sovereignty and the eventual dissolution of the Soviet Union.

Andrey Vyshinsky was the Chief Prosecutor during the Great Purges, known for his role in the Moscow Show Trials. Nikolai Bukharin, listed as the correct option, was actually a prominent victim of these purges and was executed in 1938. The provided answer key identifies Bukharin as the prosecutor, which contradicts historical evidence regarding his role as a defendant and victim of the Stalinist purges.

Lenin's primary contributions to Marxism include the theory of the vanguard party, the analysis of imperialism as the highest stage of capitalism, and the strategy for revolution in agrarian societies. Since the options provided focus on concepts primarily developed by Marx (labour theory of value, surplus value), they are incorrect. Lenin expanded Marxism into 'Marxism-Leninism' by focusing on political organization and global capitalist dynamics rather than just economic theory.

The 1918 Russian Soviet Federative Socialist Republic Constitution was the first constitution of the new Soviet state. Its explicit goal was to formalize the 'dictatorship of the proletariat,' a Marxist concept where the working class holds political power to suppress the bourgeoisie and transition toward a socialist society. It rejected liberal democratic structures in favor of a system based on workers' councils, or soviets, to consolidate Bolshevik authority.

The disintegration of the USSR was caused by a complex interplay of internal economic stagnation, political reforms like Glasnost and Perestroika, and rising nationalism within the Soviet republics. Attributing the collapse to India is historically inaccurate, as India maintained friendly relations with the Soviet Union throughout the Cold War. The other statements correctly identify the ideological roots, leadership, and economic transition processes of the era.

The acronym U.S.S.R. stands for the Union of Soviet Socialist Republics. This name reflects the federal nature of the state, which was organized as a union of various socialist republics governed by councils known as 'soviets.' It served as the official title of the country from its formation in 1922 until its collapse in 1991.

Pyotr Nikolayevich Wrangel, known as General Wrangel, was a commander of the White Army during the Russian Civil War. After taking command of the White forces in the south, he established a government in Crimea in 1920, which served as the final major stronghold for the anti-Bolshevik movement before its collapse later that year.

Following the death of Vladimir Lenin in 1924, a power struggle ensued within the Communist Party of the Soviet Union. Joseph Stalin, who held the position of General Secretary, successfully outmaneuvered his rivals, including Leon Trotsky, to consolidate control. Stalin subsequently established a centralized, authoritarian regime, leading the USSR through rapid industrialization and the Second World War until his death in 1953.

While the concept originated with Marx and Engels, Vladimir Lenin provided the most comprehensive and practical elaboration of the 'dictatorship of the proletariat' in his work 'The State and Revolution'. He defined it as the transitional phase between capitalism and communism, where the working class exercises state power to dismantle the bourgeois state apparatus.