Which of the following statements is false?

a. If the discount (or interest) rate is positive, the future value of an expected series of payments will always exceed the present value of the same series.

b. To increase present consumption beyond present income normally requires either the payment of interest or else an opportunity cost of interest foregone.

c. Disregarding risk, if money has time value, it is impossible for the present value of a given sum to be greater than its future value.

d. Disregarding risk, if the present value of a sum is equal to its future value, either r = 0 or t = 0.

e. Each of the above statements is true.