Honey Bee is thinking about purchasing a new clam maker for $14,000. The expected net cash flows resulting from the digger are $9,000 in year 1, $7,000 in the 2nd year, $5,000 in the 3rd year, and $3,000 in the 4th year. Assuming that the cost of capital is 12 percent what is the MIRR for the project?

A. 35%

B. 30%

C. 21%

D. 28%

E. 13%

(Please don't answer "20.9 or 13% approx" as this can be taken to mean that either C. 21% or E. 13% are both the answer and my prof states that 21% is the answer yet some continue to state that its 13%, please help)