Lawrence Corp. is considering the purchase of a new piece of equipment. When discounted at a hurdle rate of 10%, the project has a net present value of $24,630. When discounted at a hurdle rate of 15%, the project has a net present value of ($28,960). The internal rate of return of the project is:

a. between 10% and 15%

b. greater than 15%

c. between zero and 10%

d. zero