The standard costs and actual costs for factory overhead for the manufacture of 2,900 units of actual production are as follows: Standard Costs 3 hours per unit at $0.79 per hour Fixed overhead (based on 10,000 hours) Variable overhead 3 hours per unit at $2.04 per hour Actual Costs Total variable cost, $17,900 Total fixed cost, $7,800 The fixed factory overhead volume variance is Oa. $822 unfavorable Ob. $822 favorable Oc. $1,027 unfavorable Od. $0