Concept:The total stock of money in an economy at a given time is known as the money supply.Explanation:The money supply refers to the total amount of money available in the economy for spending and transactions.It includes currency, demand deposits, and other liquid assets held by the public.The money supply is not a function or characteristic of money, nor is it the demand for money.It represents the actual quantity of money circulating, which economists call the supply of money.Answer:D. the supply of money