Aproject has costs of $10 million per year for 10 years. the benefits of $30 million per year occur in years 7, 8, 9, and 10. at a 5% discount rate, is this project socially desirable? (assume that costs and benefits accrue on the last day of each year).

a. the project is socially desirable; net benefits are $2.2 million.
b. the project is socially undesirable; net benefits are –$20 million.
c. the project is socially undesirable; net benefits are –$0.7 million.
d. the project is socially desirable; net benefits are $20 million