The following labor standards have been established for a particular product: Standard hours per unit of output................. 6.3 hours Standard variable overhead rate................... $ 18.65 per hour The following data pertain to operations concerning the product for the last month: Actual hours.............................................. 8,600 hours Actual total variable overhead cost............. $ 157,380 Actual output............................................. 1,100 What is the variable overhead efficiency variance for the month? $30,561 U $31,146 U $28,136 U $2,426 U