Which of the Following Does Not Reflect a Positive Rate

Multiple Choice

Which of the following does not reflect a positive rate of time preference?

A) Concert-goers yell and scream when the stage is still dark an hour after the concert was scheduled to start.
B) Borrowers have to pay interest on loans.
C) A dieter, allowed three ounces of butter per day, spends the whole allotment on her toast at breakfast.
D) A dieter, allowed three ounces of butter per day, promises himself some new clothes if he can break the habit of spending the whole allotment on his toast at breakfast.
E) A student stays up late every night for a week to finish her term paper two months before it is due.