There are three mutually exclusive project, where the basic information is provided below. Assume a DN alternative does not exist. 4) $25,000 S6,000 Infinity S30,000 $32,000 $6500 Infinity $45,000 Initial Cost $38,000 Annual net profit Useful Life Infinity Salvage value $50,000 a) Using the incremental cost analysis, calculate the incremental rate of return for each switch? b) Assuming MARR Is 10% per year, what would be your final decision? c) If the DN exist, do your decision change? Why