Giannitti Corporation bases its predetermined overhead rate on the estimated machine-hours for the upcoming year. Data for the upcoming year appear below: Estimated machine-hours 72,900 Estimated variable manufacturing overhead $ 3.50 per machine-hour Estimated total fixed manufacturing overhead $ 838,800 The predetermined overhead rate for the recently completed year was closest to: a. $6.66 per machine-hour b. $10.50 per machine-hour c. $15.01 per machine-hour d. $8.69 per machine-hour