Saalfrank Corporation is considering two alternatives that are code-named M and N. Costs associated with the alternatives are listed below: Supplies costs Assembly costs Power costs Inspection costs Required: Alternative M Alternative N $ 49,500 $ 33,000 $13,000 $ 52,000 $ 33,000 $ 20,000 $ 26,000 $ 15,000 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?