Correct answer: C. Nationalisation of banks
Explanation: In the April Theses, Lenin demanded the nationalisation of banks as part of a wider socialist programme. Nationalisation meant transferring ownership and control from private financiers to the state. Lenin believed that state control over banking would allow credit, savings and financial resources to be coordinated according to public and revolutionary priorities rather than private profit. This proposal did not mean that banks would simply be closed, because banking functions would continue under public control. It also did not involve giving banks to private traders or moving them abroad. Therefore, option C is correct because it precisely expresses Lenin’s demand for state ownership and control of banks.