The aggregate demand curve representing the aggregate willingness to pay for a public good is found by:
A. Adding up the quantity demanded by each person at each and every price level
B. Adding up the willingness to pay of each person at each and every level of the public good
C. Multiplying the willingness to pay of each person by the quantity that each is willing to purchase
D. Adding up the willingness to pay of each person and then dividing by the total number of people