Explanation:

- When the commodity value (the value of the physical substance) is less than its monetary value (face value), this type of money is called credit money.

- Option 3: credit money is correct. Credit money is accepted as payment, though its intrinsic value is less than what it represents.

- Option 1: Fiat money is money by law, with no intrinsic commodity value but is not specifically defined by the difference between commodity and face value.

- Option 2: Fiduciary money is money accepted due to trust, often not fully backed by a commodity.

- Option 4: Full bodied money (like gold coins) has commodity value equal to its monetary value.