Answer :
In the early 1920s, Lenin established the New Economic Policy, which reversed earlier changes and gave the economy a boost.
Option C reversed earlier changes and gave the economy a boost is a right answer.
Vladimir Lenin in 1921, introduced a New Economy Policy for Soviet Russia. This New Economy outlined a more market-determined financial policy, to boost the economy of Russia.
The economy of Russia suffered firmly since 1914. The Soviet officials partially reversed the complete nationalization of industries, which were founded during the Communism war period (1918 to 1921). Lenin and proposed a system of mixed economics which permitted private individuals to own small businesses, whereas, the control of banks, large industries, and foreign trade was in the hand of the government.