21. A drill press costs $30,000 and is expected to have a 10 year life. The drill press will be depreciated on a straight-line basis over 10 years to a zero estimated salvage value. This machine is expected to reduce the firm’s cash operating costs by $4,500 per year. If the firm is in the 40 percent marginal tax bracket, determine the annual net cash flows generated by the drill press. 

a. $4,500 

b. $900 

c. $5,700 

d. $3,900