Panther Corporation uses a predetermined overhead rate based on machine-hours to apply manufacturing overhead to jobs. T Corporation has provided the following estimated costs for next year: 1,000 3,000 4,000 Direct materials $ Direct labor $ Sales commissions $ Salary of production $ supervisor Indirect materials $ Advertising expense $ Rent on factory $ equipment 2,000 400 800 2,000 Panther estimates that 500 direct labor-hours and 1,000 machine-hours will be worked during the year. The predetermined ove rate per hour will be: Select one: a. $6.00 per machine-hour b. $3.40 per machine-hour c. $4.40 per machine-hour d. $4.80 per machine-hour