Skate Magic manufactures three different product lines, Model TS, Model AY, and Model GG. Considerable market demand exists for all models. The following per unit data apply: Model TS Model AY Model GG $100 $120$140 12 24 Selling price Direct materials Direct labot ($12 per hour) Variable support costs ($4 per machine-hour) Fixed support costs 12 24 12 48 8 20 16 20 16 20 Which model has the greatest contribution margin per machine-hour? A) Model TS B) Model AY C) Model GG D) both Models YA and GG