The Plastechnics Company began operations several years ago. The company's product requires materials that cost $25 per unit. The company employs a production supervisor whose salary is $2,000 per month. Production line workers are paid $15 per hour to manufacture and assemble the product The company rents the equipment needed to produce the product at a rental cost of $1, 500 per month. The building is depreciated on the straight-line basis at $9,000 per year. The company spends $40,000 per year to market the product Shipping costs for each unit are $20 per unit. The company plans to liquidate several investments in order to expand production. These investments currently earn a return of $8,000 per year. Required: Complete the answer sheet below by placing an "X" under each heading that identifies the cost involved. The "Xs" can be placed under more than one heading for a single cost e.g., a cost might be a sunk cost, an overhead cost and a product cost