Option 1 -> CRR is a monetary policy tool where RBI mandates banks to maintain reserves.
Option 2 -> Bank Rate is the rate at which RBI lends to commercial banks, a key monetary tool.
Option 3 -> Public Expenditure is a fiscal policy tool controlled by the government, not RBI.
Option 4 -> Open Market Operations involve buying/selling government securities by RBI to control money supply.
Hence, Option 3: Change in Public Expenditure -> Public expenditure is a fiscal policy measure controlled by the government through its budget allocation and spending decisions. The Reserve Bank of India handles monetary policy (CRR, Bank Rate, OMO, Repo Rate, etc.) which controls money supply and credit in the economy, while fiscal policy including public expenditure is the domain of the Ministry of Finance and the government -> correct