Question 4.7 (10pts) A city government is considering two types of town-dump sanitary systems. Design A requires an initial outlay of $500,000 with annual operating and maintenance costs of $60,000 for the next 12 years; design B calls for an investment of $400,000 with annual operating and maintenance costs of $70,000 per year for the next 12 years. Fee collections from the residents would be $65,000 per year for both systems. The interest rate is 15%, and no salvage value is associated with either system. Using the incremental PI (i) criterion, which system should be selected? A) Select design A. B) Select design B. c) We will not be able to compute the PI(i) ratio. D) Answers A, B and C are not correct