The correct option is 1 and 2 because both the bank rate and open market operations are key tools of the monetary policy used by the Reserve Bank of India (RBI) to regulate the money supply and maintain economic stability. The bank rate influences the cost of borrowing for commercial banks, thereby affecting interest rates in the economy, while open market operations involve the buying and selling of government securities to control liquidity. In contrast, public debt and public revenue pertain to fiscal policy, which is concerned with government spending and taxation rather than the management of the money supply. This distinction is crucial for understanding the broader framework of economic policy in India as covered in standard UPSC reference materials.