The bank rate and reserve money are the monetary tools of RBI to regulate the money flow with ...........

1. Cooperative banks
2. External banks
3. Central bank
4. Commercial banks

Option 1 -> Cooperative banks are smaller, community-focused banks not primarily regulated by these monetary tools.

Option 2 -> External banks is not a standard term in RBI's monetary policy framework.

Option 3 -> Central bank refers to RBI itself; it cannot regulate money flow with itself.

Option 4 -> Commercial banks are the primary financial institutions through which RBI implements monetary policy.

Hence, Commercial banks -> The RBI uses bank rate (the rate at which it lends to commercial banks) and reserve money requirements (like CRR - Cash Reserve Ratio and SLR - Statutory Liquidity Ratio) as key monetary policy tools to regulate money supply in the economy. Commercial banks are the primary channels through which RBI's monetary policy is transmitted to the broader economy. By adjusting the bank rate, RBI influences the cost of borrowing for commercial banks, which in turn affects lending rates to customers. Reserve requirements determine how much money commercial banks must keep as reserves, directly affecting their lending capacity and the overall money supply. -> correct