Which one of the following statements about value in use is true? a. John bought groceries for $50, so his PIBP for the groceries was $50. b. My PIBP for two identical items can be, at most, twice my...

Which one of the following statements about value in use is true?

a. John bought groceries for $50, so his PIBP for the groceries was $50.

b. My PIBP for two identical items can be, at most, twice my PIBP for one item.

c. My PIBP for a ticket to the Big Game must remain constant until game day.

d. Xi sold his helmet for $20, so his PISP for the helmet was at most $20.