Safira Limited has budgeted its production overhead costs for the forthcoming year to be as follows: fixed, 175,000; variable, 4 per unit. Safira has budgeted to produce 350,000 units annually. By the end of the year, it had incurred production overheads totalling 1,600,000 and produced 400,000 units. What would be the overhead absorption rate (for fixed and variable costs combined) that Safira Limited would have used to absorb (recharge) production overhead costs to its output? Select one: a. 3.50/unit b. 4.50/unit C. 9.00/unit d. 5.50/unit