The following standards for variable manufacturing overhead have been established for a company that makes only one product: Standard hours per unit of output Standard variable overhead rate 6.0 hours $12.40 per hour The following data pertain to operations for the last month: Actual hours Actual total variable manufacturing overhead cost Actual output 2,600 hours $32,870 250 units What is the variable overhead efficiency variance for the month? Multiple Choice 0 $14,270 U 0 $13.640 U 0 $6300 O $18.600 F