Explanation:

- Option 1: Government of the country

- The government plays a role in the monetary system, mainly through fiscal policies and issuing currency.

- However, it is not the direct and only supplier of money.

- Option 2: Banking system of the country

- The banking system, including the central bank, is a major supplier of money.

- It directly influences the money supply through monetary policies, lending, and managing reserves.

- Option 3: Both a) and b)

- The supply of money involves both the government and the banking system.

- The central bank, part of the banking system, works in conjunction with government policies.

- Option 4: None of these

- This option isn't correct as elements of both the government and the banking system are involved in money supply.

Correct Answer: Option 3 - Both a) and b)