Consider three mutually exclusive alternatives. The MARR is 10%. Year X Y Z 0 -$100-$50 -$50 I 25 16 21 2 25 16 21 3 25 1621 4 25 16 21 (a) For Alt. X, compute the benefit-cost ratio. (b) Based on the payback period, which alternative should be selected? (c) Determine the preferred alternative based on an (c) Determine the preferred alternative based on an