Pfizer Corporation is considering a machine that will save $8,000 a year in cash operating costs each year for the next eight years. At the end of eight years, it would have no salvage value. If this machine costs $44,280 now, the machine's internal rate of return is closest to (Ignore income taxes.): O a. 8% O b. 12% O c. 11% Od. 10% Oe. 9%