RC Ltd, which uses a standard cost system, budgeted $800,000 of fixed overhead when 45,000 machine hours were anticipated. Other data for the period were: Actual units produced: 10,500 Actual machine hours worked: 49,500 Actual variable overhead incurred: $425,000 Actual fixed overhead incurred: $790,100 Standard variable overhead rate per machine hour: $7.80 Standard production time per unit: 4.5 hours The company's variable-overhead efficiency variance is: $56,450U. $17,550U. $17,550F. None of the listed choices. $38,900F