8. refer to the diagrams in which figures (a) and (b) show demand curves reflecting the prices alvin and elmer are willing to pay for a public good, rather than do without it. the collective willingness to pay for the first unit of this public good is: a. $18. b. $14. c. $10. d. $6. why? explain your answer. refer to the diagrams in which figures (a) and (b) show demand curves reflecting the prices alvin and elmer are willing to pay for a public good, rather than do without it. at which price the alvin & elmer willingness to pay is equal to zero unit of this public good are respectively: why? explain your answer.