4. (4 points) Fort, Inc incurred $128,730 of actual manufacturing overhead cost last year. The company used a predetermined overhead rate of $3 per direct labor hour. At the end of the reporting period, the company's manufacturing overhead account has a debit balance of $4,500. How many direct labor hours were worked last year? a. 42,410 hours b. 38,410 hours c. 40,190 hours d. 13,500 hours e. 42,910 hours f. 44,410 hours g. 41,410 hours h. None of the above