Rich Company, which uses a standard cost system, budgeted $800,000 of fixed overhead when 50,000 machine hours were ipated. Other data for the period were: Actual units produced: 10,600 Actual machine hours worked: 51,800 Actual variable overhead incurred: $475,000 Actual fixed overhead incurred: $790,100 Standard variable overhead rate per machine hour: $8.50 Standard production time per unit: 5 hours Rich's variable-overhead efficiency variance is: A. $10,2000. B. $10,200F. C. $15,300U. D. $15,300F O