53. hadley, inc. manufactures a product that uses $15 in direct materials and $5 in direct labor per unit. under the traditional costing system hadley uses, manufacturing overhead applied to each unit is $12. however, hadley is considering switching to an abc system. under the abc system, the total activity cost would be $25. what is the total manufacturing cost per unit for hadley under the abc system? a. $20 b. $25 c. $32 d. $45