The statement that oatmeal is an inferior good, as economists use the term

a. means that as the price of oatmeal falls, the quantity demanded of oatmeal falls

b. means that there is no real income effect when the price of oatmeal changes

c. is an example of a normative statement

d. means that as the average level of income falls, the demand for oatmeal rises

e. means that the supply of oatmeal is perfectly inelastic