请教一道题

An analyst has been hired to evaluate a high-risk project. The analyst estimates the probability that the project will fail in the first year as well as the conditional probability of failure for each of the remaining four years of the project, as follows:

year                         1                2                  3                 4                5

failure probability   0.25          0.20              0.20            0.15           0.10

The project will have no payoff if it fails, but will have a payoff of $20,000 at the end of the fifth year if it succeeds. Because of its high risk, the required rate of the return for an investment in this project is 25%. Based on this information, the expected present value of the project is closest to :

a 2400

b 3010

c 5900

d 6550

请问这道题怎么解啊？谢谢帮助。