Baher Company manufactures three different product lines, ABC, KLM, and XYZ. Considerable market demand exists for all models. The following per unit data apply: ABC KLM XYZ Selling Price $ 60 $ 70 $ 80 Direct materials $ 6 $9 $ 11 Direct labor ($8 per hour) $ 12 $ 16 $ 24 Variable support costs ($6 $ 12 $9 $ 18 per machine hour) Fixed support costs $ 12 $ 12 $ 12 Which model has the greatest contribution margin per machine-hour? a. Model XYZ b. Models ABC & XYZ C. Model KLM d. Model ABC