The standard costs and actual costs for factory overhead for the manufacture of 2,900 units of actual production are as follows: Standard Costs Fixed overhead (based on 10,000 hours) 3 hours per unit at $0.75 per hour Variable overhead 3 hours per unit at $2.06 per hour Actual Costs Total variable cost, $18,100 Total fixed cost, $7,800 The fixed factory overhead volume variance is a. $780 favorable b. $975 unfavorable C. SO d. $780 unfavorable