Firm BCD has the opportunity to invest in one of two mutually exclusive machines, which can both produce the same product. Machine A has a life of 9 years, costs $12 million and will produce after-tax inflows of $2.5 million per year at the end of each year. Machine B has a life of 7 years, costs $15 million and will produce after-tax inflows of $3.5 million per year at the end of each year. Assuming that the machines can be replaced indefinitely at constant prices, which machine should BCD choose? Assume a cost of capital of 12%.