Project 1 requires an initial investment of $60,000 and has an IRR = 18%. A mutually exclusive alternative, Project 2, requires an investment of $80,000 and has an IRR = 23%. Which of the following statements is true concerning the rate of return on the incremental $20,000 investment?

a) it is less than 18%

b) it is between 18 and 23%

c) it is greater than 23%

d) it cannont be determined from the data given