4. Suppose you have an opportunity to invest in a project, which is expected to generate $5000 in year 1, $7000 in year 2, and $8000 in year 3. The appropriate discount rate for the project is 10%. What is the initial investment of the project when the project's NPV is $4000?

a. $17,609.25

b. $12,341.09

c. 21,500.00

d. $20,218.50