Which of the following does not explain why is there an inverse (negative) relationship between price and quantity demanded?
A. Income effect--that is, a price change can affect the amount of some item you can afford to purchase
B. Substitution effect -- that is, a price change can affect the opportunity cost of purchasing some item and your willingness to switch to ( or from) another item.
C. Diminishing marginal utility-- as you consumer more, as the result of price decrease, the additional satisfaction received from the additional units consumer will start to go
D. When the price of an item increases, you buy more because it is more valuable