Calculator Sabor Inc. is a medical testing laboratory that performs several tests and analyses for hospitals in the area. Four of the tests that they perform require the use of a specialized machine that can supply 14,000 hours per year. Information on the four lab tests follows: 348 Test B Test A Test C Test D $32 Charging rate $65 Variable cose Machine hours What is the contribution margin per unit of machine time for Test D? a $20 b. $24 c. $48 d. $32 e 58 A 0011/3/20