Saalfrank Corporation is considering two alternatives that are code-named M and N. Costs associated with the alternatives are listed below: Alternative M Alternative N Supplies costs $ 49,500 $ 52,000 Assembly costs $ 33.000 $ 33,000 Power costs $ 13,000 $ 20,000 Inspection costs $ 26,000 $ 15,000 Required: a. Which costs are relevant and which are not relevant in the choice between these two alternatives? b. What is the differential cost between the two alternatives