4. Suppose you have an opportunity to invest in a project, which is expected to generate $5,000 in year 1, $7,000 in year 2, and $8,000 in year 3. The appropriate discount rate for the project is 10 percent. What is the initial investment of the project when the project's NPV is $4,000?

a. $17,609.25

b. $12,341.09

c. 21,500.00

d. $20,218.50