A social project requires an initial investment of $5,000,000 which will be made in year "0". According to the market study, users will demand an amount of 12,000 units per year. The social price per service unit is $100 (determined by PECEP). The variable costs per unit of service (at social value) are: Materials $30 Workforce $25 Various Expenses $10 In addition, it is recognized that the project generates a positive externality with a value of $2,200 per year (total value during each year). According to the PECEP, the social discount rate is 16% for the first 3 years and 11% for the rest. The initial investment is estimated to have a salvage/scrap value of $1,500,000 after the 12-year life of the project. a) Elaborate the cash flow. b) Calculate the NPV and IRR. (show the procedure) c) Highlight the advantages and disadvantages for each of the two criteria. d) Is the IRR a rate of return? Justify your answer P.S Pls do it manually cuz I need to know how do it without the use of programs (SHOW THE FORMULAS YOU USED TO SOLVE THE PROBLEM)