The standard costs and actual costs for factory overhead for the manufacture of 2,600 units of actual production are as follows: Standard Costs Fixed overhead (based on 10,000 hours) 3 hours per unit at $0.74 per hour Variable overhead Actual Costs Total variable cost, $17,800 3 hours per unit at $1.93 per hour Total fixed cost, $7,900 The variable factory overhead controllable variance is Oa. $0 Ob. $2,746 favorable Oc. $2,746 unfavorable Od. $2,197 favorable