Suppose that a company has to choose between machine A and machine B, with initial investments of 120,000 and 150,000, respectively. Both machines can do the same job, but they have different operating costs and will last for different time periods. Machine A lasts three years; its maintenance expenses of 1,200 should be paid at the end of each year. Machine B lasts four years; its maintenance expenses of $1,000 should be paid at the end of each year. The appropriate discount rate is 12%. Which machine, A or B, is preferred?