The following information is related to Alpha Company: Estimated manufacturing overhead costs for the year $249,000 Actual manufacturing overhead costs for the year $201,000 Estimated direct labor hours for the year 50,000 Actual direct labor hours for the year 34,000 Alpha uses normal costing and applies overhead on the basis of direct labor hours. The predetermined overhead rate of Alpha Company is: O a. a. $5.0 per hour. O b. $7.3 per hour. O c. $8.7 per hour. O d. $4.0 per hour. Normal costing determines unit cost by adding: O a. direct materials, direct labor, and underapplied overhead. O b. direct materials, direct labor, and overapplied overhead. O c. direct materials, direct labor, and estimated overhead. d. direct materials, direct labor, and actual overhead