PFM Plc is considering the purchase of a new machine. It has identified two possible machines with initial costs and expected cash savings per year as follows: Machine A Machine B Co -20,000 -20,000 C C C3 3,000 5,500 6,000 5,000 6,500 7,300 C4 7,200 5,000 C5 4,000 Machine A has a useful life of 5 years while machine B has a useful life of 4 years. Neither of these machines has any residual value at the end of their lives. The two machines are mutually exclusive. The opportunity cost of capital for PFM Plc is 5% per year. If PFM Plc is going to replace the chosen machine each time when it reaches the end of its useful life, which machine would you recommend the management to invest? return of machine A? using the discount rate 6% and 20%, what is the internal rate of