Explanation:

- Money Supply generally refers to the total amount of monetary assets available in an economy at a specific time. It involves different categories:

- Option 1: Money deposits in the bank

- This includes saving and time deposits, which are key elements of certain money supply measures, like M2 and M3.

- Option 2: Cash available with the public

- This refers to the physical currency people are holding and is a direct component of money supply measures, like M0 and M1.

- Option 3: Savings in the post office

- These are forms of savings that may also be considered in broader definitions of money supply, depending on national accounting practices.

- Option 4: All of the above

- This is correct because the full money supply includes various deposits and cash within the economy.