Cost allocation in a manufacturing company Solid Door Corporation makes a particular type of door. The labor cost is $90 per door and the material cost is $160 per door. Solid rents a factory building for $60,000 a month. Solid plans to produce 24,000 doors annually. In March and April, it made 2,000 and 3,000 doors, respectively. 

Required

a. Explain how changes in the cost driver (number of doors made) affect the total amount of fixed rental cost.

b. Explain how changes in the cost driver (number of doors made) affect the fixed rental cost per unit.

c. If the cost objective is to determine the cost per door, is the factory rent a direct or an indirect cost?

d. How much of the factory rent should be allocated to doors produced in March and April?