Two mutually exclusive alternatives are under consideration. Alt A. will cost $40,000, provide annual benefits of $15,000 and a salvage of $4000 at the end of its 4 year life. Alternate B will cost $63,000, provide annual benefits of $21,000, and a salvage of $5000 at the end of its 4 year life. Use IRR techniques to make a recommendation. An incremental approach is needed.