Which of the Following Is True

Which of the following is true?

A) If the consumer is a buyer of several units of a good, the earlier units will have greater marginal value and therefore create more consumer surplus, because marginal willingness to pay falls as greater quantities are consumed in any period.
B) When some units of output can be produced at a cost that is lower than the market price, the seller receives a surplus, or net benefit, from producing those units.
C) Producer surplus is shown graphically as the area under the price and above the supply curve.
D) At the market equilibrium both consumers and producers benefit from trading every unit up to the market equilibrium output.
E) All of the above are true.