process improvements. D. activity based pricing. Narly Skateboards manufactures three different product lines, Base, Long, and Trick. Considerable market demand exists for all models. The following per unit data apply: Base Model Long Model Trick Model $100 120 S 140 12 48 Direct materials Direct labor (512 per hour) Variable support costs (54 per machine- hour) Fixed support costs 20 Which model has the greatest contribution margin per unit? Select one: A long model B. trick model C. base model D. both the base model and the long model Narty Skateboards manufactures three different product lines Base Long and Trick. Considerable market demand exists for all models. The following