Explanation:

- Monopoly of Note Issue: The central bank is typically the sole authority to issue banknotes, ensuring consistency and control over the currency supply.

- Banker of the Government: The central bank manages the government's funds, processes payments, and may handle public debt. It acts as the government's financial agent.

- Custodian of Foreign Exchange Reserves: The central bank holds and manages the country's foreign exchange reserves, crucial for international trade and exchange rate stability.

- All the above: The central bank performs all these functions, making it pivotal for economic stability and policy implementation.