Chris Co$.$ is considering replacing an old machine that was purchased for $$100,000.$ It has a current book value of $$40,000$ and should last four more years. The new $($replacement$)$ machine costs $$70,000$ and will have a $4-$year life and a $$30,000$ salvage value. If the machine is purchased, the old machine can be sold for $$20,000.$ It cost $$20,000$ annually to operate the old machine. The new machine is more efficient and should reduce operating cost by $50\%.$ Chris should Blank$\_\_\_\_\_\_$ than the old machine.

Multiple choice question.