The following information was taken from the annual manufacturing overhead cost budget of Frog Manufacturing Variable manufacturing overhead costs 592.400 Fixed manufacturing overhead costs 535,440 Normal production level in labor hours 30,800 Normal production level in units 5,775 Standard labor hours per unit 4 During the year, 5,600 units were produced, 18,340 hours were worked, and the actual manufacturing overhead was 5151,200. Actual fixed manufacturing overhead costs equaled budgeted fixed manufacturing overhead costs. Overhead is applied on the basis of direct labor hours. Frog's total overhead variance is A $1,680 U. B. 56,160 U C. 57,840 U D. 522,400 U