Please show me how to solve this problem in accounting three.

At the beginning of the year, manufacturing overhead for the year was estimated to be $702, 450. At the end of the year, actual direct labor-hours for the year were 33, 100 hours, the actual manufacturing overhead for the year was $697, 450, and manufacturing overhead for the year was over applied by $40, 680. If the predetermined overhead rate is based on direct labor-hours, then the estimated direct labor-hours at the beginning of the year used in the predetermined overhead rate must have been: A. 31, 500 direct labor-hours B. 29, 452 direct labor-hours C. 31, 276 direct labor-hours D. 33, 100 direct labor-hours